diff --git a/Gemfile b/Gemfile
index bd91a5a41366e..29b52bbc282fe 100644
--- a/Gemfile
+++ b/Gemfile
@@ -149,6 +149,7 @@ platforms :ruby, :windows do
   group :db do
     gem "pg", "~> 1.3"
     gem "mysql2", "~> 0.5"
+    gem "trilogy", "~> 2.4"
   end
 end
 
diff --git a/Gemfile.lock b/Gemfile.lock
index 9039bb8adb956..7b7605f91919a 100644
--- a/Gemfile.lock
+++ b/Gemfile.lock
@@ -507,6 +507,7 @@ GEM
     timeout (0.3.2)
     tomlrb (2.0.3)
     trailblazer-option (0.1.2)
+    trilogy (2.4.0)
     turbo-rails (1.3.2)
       actionpack (>= 6.0.0)
       activejob (>= 6.0.0)
@@ -617,6 +618,7 @@ DEPENDENCIES
   sucker_punch
   tailwindcss-rails
   terser (>= 1.1.4)
+  trilogy (~> 2.4)
   turbo-rails
   tzinfo-data
   w3c_validators (~> 1.3.6)
diff --git a/activerecord/CHANGELOG.md b/activerecord/CHANGELOG.md
index 013b2ac5c8005..9f58d32d0cb99 100644
--- a/activerecord/CHANGELOG.md
+++ b/activerecord/CHANGELOG.md
@@ -1,3 +1,23 @@
+*   Introduce adapter for Trilogy database client
+
+    Trilogy is a MySQL-compatible database client. Rails applications can use Trilogy
+    by configuring their `config/database.yml`:
+
+    ```yaml
+    development:
+    adapter: trilogy
+    database: blog_development
+    pool: 5
+    ```
+
+    Or by using the `DATABASE_URL` environment variable:
+
+    ```ruby
+    ENV['DATABASE_URL'] # => "trilogy://localhost/blog_development?pool=5"
+    ```
+
+    *Adrianna Chang*
+
 *   `after_commit` callbacks defined on models now execute in the correct order.
 
     ```ruby
diff --git a/activerecord/RUNNING_UNIT_TESTS.rdoc b/activerecord/RUNNING_UNIT_TESTS.rdoc
index 95a87807b8a69..a048463edd15a 100644
--- a/activerecord/RUNNING_UNIT_TESTS.rdoc
+++ b/activerecord/RUNNING_UNIT_TESTS.rdoc
@@ -21,6 +21,7 @@ example:
 Simply executing <tt>bundle exec rake test</tt> is equivalent to the following:
 
   $ bundle exec rake test:mysql2
+  $ bundle exec rake test:trilogy
   $ bundle exec rake test:postgresql
   $ bundle exec rake test:sqlite3
 
diff --git a/activerecord/Rakefile b/activerecord/Rakefile
index 51a59f14e6eb6..fd9c0eafbc100 100644
--- a/activerecord/Rakefile
+++ b/activerecord/Rakefile
@@ -18,16 +18,16 @@ def run_without_aborting(*tasks)
   abort "Errors running #{errors.join(', ')}" if errors.any?
 end
 
-desc "Run mysql2, sqlite, and postgresql tests by default"
+desc "Run mysql2, trilogy, sqlite, and postgresql tests by default"
 task default: :test
 
 task :package
 
-desc "Run mysql2, sqlite, and postgresql tests"
+desc "Run mysql2, trilogy, sqlite, and postgresql tests"
 task :test do
   tasks = defined?(JRUBY_VERSION) ?
     %w(test_jdbcmysql test_jdbcsqlite3 test_jdbcpostgresql) :
-    %w(test_mysql2 test_sqlite3 test_postgresql)
+    %w(test_mysql2 test_trilogy test_sqlite3 test_postgresql)
   run_without_aborting(*tasks)
 end
 
@@ -35,7 +35,7 @@ namespace :test do
   task :isolated do
     tasks = defined?(JRUBY_VERSION) ?
       %w(isolated_test_jdbcmysql isolated_test_jdbcsqlite3 isolated_test_jdbcpostgresql) :
-      %w(isolated_test_mysql2 isolated_test_sqlite3 isolated_test_postgresql)
+      %w(isolated_test_mysql2 isolated_test_trilogy isolated_test_sqlite3 isolated_test_postgresql)
     run_without_aborting(*tasks)
   end
 
@@ -56,7 +56,7 @@ namespace :db do
   task drop: ["db:mysql:drop", "db:postgresql:drop"]
 end
 
-%w( mysql2 postgresql sqlite3 sqlite3_mem oracle jdbcmysql jdbcpostgresql jdbcsqlite3 jdbcderby jdbch2 jdbchsqldb ).each do |adapter|
+%w( mysql2 trilogy postgresql sqlite3 sqlite3_mem oracle jdbcmysql jdbcpostgresql jdbcsqlite3 jdbcderby jdbch2 jdbchsqldb ).each do |adapter|
   namespace :test do
     Rake::TestTask.new(adapter => "#{adapter}:env") do |t|
       adapter_short = adapter[/^[a-z0-9]+/]
@@ -64,10 +64,11 @@ end
       files = (FileList["test/cases/**/*_test.rb"].reject {
         |x| x.include?("/adapters/") || x.include?("/encryption/performance")
       } + FileList["test/cases/adapters/#{adapter_short}/**/*_test.rb"])
-      files = files + FileList["test/cases/adapters/abstract_mysql_adapter/**/*_test.rb"] if adapter == "mysql2"
+      files = files + FileList["test/cases/adapters/abstract_mysql_adapter/**/*_test.rb"] if ["mysql2", "trilogy"].include?(adapter)
 
       t.test_files = files
 
+      t.test_files = files
       t.warning = true
       t.verbose = true
       t.ruby_opts = ["--dev"] if defined?(JRUBY_VERSION)
diff --git a/activerecord/bin/test b/activerecord/bin/test
index 0c911085d76cf..872f80fa99ff5 100755
--- a/activerecord/bin/test
+++ b/activerecord/bin/test
@@ -15,7 +15,7 @@ module Minitest
     opts.separator ""
     opts.separator "Active Record options:"
     opts.on("-a", "--adapter [ADAPTER]",
-            "Run tests using a specific adapter (sqlite3, sqlite3_mem, mysql2, postgresql)") do |adapter|
+            "Run tests using a specific adapter (sqlite3, sqlite3_mem, mysql2, trilogy, postgresql)") do |adapter|
       ENV["ARCONN"] = adapter.strip
     end
 
diff --git a/activerecord/lib/active_record/connection_adapters/trilogy/errors.rb b/activerecord/lib/active_record/connection_adapters/trilogy/errors.rb
new file mode 100644
index 0000000000000..dfd9ca3dcc677
--- /dev/null
+++ b/activerecord/lib/active_record/connection_adapters/trilogy/errors.rb
@@ -0,0 +1,49 @@
+# frozen_string_literal: true
+
+module ActiveRecord
+  module ConnectionAdapters
+    module Trilogy
+      module Errors
+        # ServerShutdown will be raised when the database server was shutdown.
+        class ServerShutdown < ActiveRecord::ConnectionFailed
+        end
+
+        # ServerLost will be raised when the database connection was lost.
+        class ServerLost < ActiveRecord::ConnectionFailed
+        end
+
+        # ServerGone will be raised when the database connection is gone.
+        class ServerGone < ActiveRecord::ConnectionFailed
+        end
+
+        # BrokenPipe will be raised when a system process connection fails.
+        class BrokenPipe < ActiveRecord::ConnectionFailed
+        end
+
+        # SocketError will be raised when Ruby encounters a network error.
+        class SocketError < ActiveRecord::ConnectionFailed
+        end
+
+        # ConnectionResetByPeer will be raised when a network connection is closed
+        # outside the sytstem process.
+        class ConnectionResetByPeer < ActiveRecord::ConnectionFailed
+        end
+
+        # ClosedConnection will be raised when the Trilogy encounters a closed
+        # connection.
+        class ClosedConnection < ActiveRecord::ConnectionFailed
+        end
+
+        # InvalidSequenceId will be raised when Trilogy ecounters an invalid sequence
+        # id.
+        class InvalidSequenceId < ActiveRecord::ConnectionFailed
+        end
+
+        # UnexpectedPacket will be raised when Trilogy ecounters an unexpected
+        # response packet.
+        class UnexpectedPacket < ActiveRecord::ConnectionFailed
+        end
+      end
+    end
+  end
+end
diff --git a/activerecord/lib/active_record/connection_adapters/trilogy/lost_connection_exception_translator.rb b/activerecord/lib/active_record/connection_adapters/trilogy/lost_connection_exception_translator.rb
new file mode 100644
index 0000000000000..8c41f49133943
--- /dev/null
+++ b/activerecord/lib/active_record/connection_adapters/trilogy/lost_connection_exception_translator.rb
@@ -0,0 +1,64 @@
+# frozen_string_literal: true
+
+module ActiveRecord
+  module ConnectionAdapters
+    module Trilogy
+      class LostConnectionExceptionTranslator
+        attr_reader :exception, :message, :error_number
+
+        def initialize(exception, message, error_number)
+          @exception = exception
+          @message = message
+          @error_number = error_number
+        end
+
+        def translate
+          translate_database_exception || translate_ruby_exception || translate_trilogy_exception
+        end
+
+        private
+          ER_SERVER_SHUTDOWN = 1053
+          CR_SERVER_LOST = 2013
+          CR_SERVER_LOST_EXTENDED = 2055
+          CR_SERVER_GONE_ERROR = 2006
+
+          def translate_database_exception
+            case error_number
+            when ER_SERVER_SHUTDOWN
+              Errors::ServerShutdown.new(message)
+            when CR_SERVER_LOST, CR_SERVER_LOST_EXTENDED
+              Errors::ServerLost.new(message)
+            when CR_SERVER_GONE_ERROR
+              Errors::ServerGone.new(message)
+            end
+          end
+
+          def translate_ruby_exception
+            case exception
+            when Errno::EPIPE
+              Errors::BrokenPipe.new(message)
+            when SocketError, IOError
+              Errors::SocketError.new(message)
+            when ::Trilogy::ConnectionError
+              if message.include?("Connection reset by peer")
+                Errors::ConnectionResetByPeer.new(message)
+              end
+            end
+          end
+
+          def translate_trilogy_exception
+            return unless exception.is_a?(::Trilogy::Error)
+
+            case message
+            when /TRILOGY_CLOSED_CONNECTION/
+              Errors::ClosedConnection.new(message)
+            when /TRILOGY_INVALID_SEQUENCE_ID/
+              Errors::InvalidSequenceId.new(message)
+            when /TRILOGY_UNEXPECTED_PACKET/
+              Errors::UnexpectedPacket.new(message)
+            end
+          end
+      end
+    end
+  end
+end
diff --git a/activerecord/lib/active_record/connection_adapters/trilogy_adapter.rb b/activerecord/lib/active_record/connection_adapters/trilogy_adapter.rb
new file mode 100644
index 0000000000000..a8bdfe84fc55a
--- /dev/null
+++ b/activerecord/lib/active_record/connection_adapters/trilogy_adapter.rb
@@ -0,0 +1,347 @@
+# frozen_string_literal: true
+
+require "active_record/connection_adapters/abstract_mysql_adapter"
+
+gem "trilogy", "~> 2.4"
+require "trilogy"
+
+require "active_record/connection_adapters/trilogy/lost_connection_exception_translator"
+require "active_record/connection_adapters/trilogy/errors"
+
+module ActiveRecord
+  module ConnectionHandling # :nodoc:
+    def trilogy_adapter_class
+      ConnectionAdapters::TrilogyAdapter
+    end
+
+    # Establishes a connection to the database that's used by all Active Record objects.
+    def trilogy_connection(config)
+      configuration = config.dup
+
+      # Set FOUND_ROWS capability on the connection so UPDATE queries returns number of rows
+      # matched rather than number of rows updated.
+      configuration[:found_rows] = true
+
+      options = [
+        configuration[:host],
+        configuration[:port],
+        configuration[:database],
+        configuration[:username],
+        configuration[:password],
+        configuration[:socket],
+        0
+      ]
+
+      trilogy_adapter_class.new nil, logger, options, configuration
+    end
+  end
+  module ConnectionAdapters
+    class TrilogyAdapter < AbstractMysqlAdapter
+      module DatabaseStatements
+        READ_QUERY = AbstractAdapter.build_read_query_regexp(
+          :desc, :describe, :set, :show, :use
+        ) # :nodoc:
+        private_constant :READ_QUERY
+
+        HIGH_PRECISION_CURRENT_TIMESTAMP = Arel.sql("CURRENT_TIMESTAMP(6)").freeze # :nodoc:
+        private_constant :HIGH_PRECISION_CURRENT_TIMESTAMP
+
+        def select_all(*, **) # :nodoc:
+          result = nil
+          with_raw_connection do |conn|
+            result = super
+            conn.next_result while conn.more_results_exist?
+          end
+          result
+        end
+
+        def write_query?(sql) # :nodoc:
+          !READ_QUERY.match?(sql)
+        rescue ArgumentError # Invalid encoding
+          !READ_QUERY.match?(sql.b)
+        end
+
+        def explain(arel, binds = [], options = [])
+          sql     = build_explain_clause(options) + " " + to_sql(arel, binds)
+          start   = Process.clock_gettime(Process::CLOCK_MONOTONIC)
+          result  = exec_query(sql, "EXPLAIN", binds)
+          elapsed = Process.clock_gettime(Process::CLOCK_MONOTONIC) - start
+
+          MySQL::ExplainPrettyPrinter.new.pp(result, elapsed)
+        end
+
+        def exec_query(sql, name = "SQL", binds = [], prepare: false, async: false)
+          result = execute(sql, name, async: async)
+          ActiveRecord::Result.new(result.fields, result.to_a)
+        end
+
+        alias exec_without_stmt exec_query
+
+        def exec_insert(sql, name, binds, pk = nil, sequence_name = nil)
+          execute(to_sql(sql, binds), name)
+        end
+
+        def exec_delete(sql, name = nil, binds = [])
+          result = execute(to_sql(sql, binds), name)
+          result.affected_rows
+        end
+
+        alias :exec_update :exec_delete
+
+        def high_precision_current_timestamp
+          HIGH_PRECISION_CURRENT_TIMESTAMP
+        end
+
+        def build_explain_clause(options = [])
+          return "EXPLAIN" if options.empty?
+
+          explain_clause = "EXPLAIN #{options.join(" ").upcase}"
+
+          if analyze_without_explain? && explain_clause.include?("ANALYZE")
+            explain_clause.sub("EXPLAIN ", "")
+          else
+            explain_clause
+          end
+        end
+
+        private
+          def last_inserted_id(result)
+            result.last_insert_id
+          end
+      end
+
+      ER_BAD_DB_ERROR = 1049
+      ER_DBACCESS_DENIED_ERROR = 1044
+      ER_ACCESS_DENIED_ERROR = 1045
+
+      ADAPTER_NAME = "Trilogy"
+
+      include DatabaseStatements
+
+      SSL_MODES = {
+        SSL_MODE_DISABLED: ::Trilogy::SSL_DISABLED,
+        SSL_MODE_PREFERRED: ::Trilogy::SSL_PREFERRED_NOVERIFY,
+        SSL_MODE_REQUIRED: ::Trilogy::SSL_REQUIRED_NOVERIFY,
+        SSL_MODE_VERIFY_CA: ::Trilogy::SSL_VERIFY_CA,
+        SSL_MODE_VERIFY_IDENTITY: ::Trilogy::SSL_VERIFY_IDENTITY
+      }.freeze
+
+      class << self
+        def new_client(config)
+          config[:ssl_mode] = parse_ssl_mode(config[:ssl_mode]) if config[:ssl_mode]
+          ::Trilogy.new(config)
+        rescue ::Trilogy::ConnectionError, ::Trilogy::ProtocolError => error
+          raise translate_connect_error(config, error)
+        end
+
+        def parse_ssl_mode(mode)
+          return mode if mode.is_a? Integer
+
+          m = mode.to_s.upcase
+          # enable Mysql2 client compatibility
+          m = "SSL_MODE_#{m}" unless m.start_with? "SSL_MODE_"
+
+          SSL_MODES.fetch(m.to_sym, mode)
+        end
+
+        def translate_connect_error(config, error)
+          case error.error_code
+          when ER_DBACCESS_DENIED_ERROR, ER_BAD_DB_ERROR
+            ActiveRecord::NoDatabaseError.db_error(config[:database])
+          when ER_ACCESS_DENIED_ERROR
+            ActiveRecord::DatabaseConnectionError.username_error(config[:username])
+          else
+            if error.message.include?(/TRILOGY_DNS_ERROR/)
+              ActiveRecord::DatabaseConnectionError.hostname_error(config[:host])
+            else
+              ActiveRecord::ConnectionNotEstablished.new(error.message)
+            end
+          end
+        end
+      end
+
+      def supports_json?
+        !mariadb? && database_version >= "5.7.8"
+      end
+
+      def supports_comments?
+        true
+      end
+
+      def supports_comments_in_create?
+        true
+      end
+
+      def supports_savepoints?
+        true
+      end
+
+      def savepoint_errors_invalidate_transactions?
+        true
+      end
+
+      def supports_lazy_transactions?
+        true
+      end
+
+      def quote_string(string)
+        with_raw_connection(allow_retry: true, uses_transaction: false) do |conn|
+          conn.escape(string)
+        end
+      end
+
+      def active?
+        connection&.ping || false
+      rescue ::Trilogy::Error
+        false
+      end
+
+      alias reset! reconnect!
+
+      def disconnect!
+        super
+        unless connection.nil?
+          connection.close
+          self.connection = nil
+        end
+      end
+
+      def discard!
+        self.connection = nil
+      end
+
+      def each_hash(result)
+        return to_enum(:each_hash, result) unless block_given?
+
+        keys = result.fields.map(&:to_sym)
+        result.rows.each do |row|
+          hash = {}
+          idx = 0
+          row.each do |value|
+            hash[keys[idx]] = value
+            idx += 1
+          end
+          yield hash
+        end
+
+        nil
+      end
+
+      def error_number(exception)
+        exception.error_code if exception.respond_to?(:error_code)
+      end
+
+      private
+        def connection
+          @raw_connection
+        end
+
+        def connection=(conn)
+          @raw_connection = conn
+        end
+
+        def connect
+          self.connection = self.class.new_client(@config)
+        end
+
+        def reconnect
+          connection&.close
+          self.connection = nil
+          connect
+        end
+
+        def sync_timezone_changes(conn)
+          # Sync any changes since connection last established.
+          if default_timezone == :local
+            conn.query_flags |= ::Trilogy::QUERY_FLAGS_LOCAL_TIMEZONE
+          else
+            conn.query_flags &= ~::Trilogy::QUERY_FLAGS_LOCAL_TIMEZONE
+          end
+        end
+
+        def execute_batch(statements, name = nil)
+          statements = statements.map { |sql| transform_query(sql) }
+          combine_multi_statements(statements).each do |statement|
+            with_raw_connection do |conn|
+              raw_execute(statement, name)
+              conn.next_result while conn.more_results_exist?
+            end
+          end
+        end
+
+        def multi_statements_enabled?
+          !!@config[:multi_statement]
+        end
+
+        def with_multi_statements
+          if multi_statements_enabled?
+            return yield
+          end
+
+          with_raw_connection do |conn|
+            conn.set_server_option(::Trilogy::SET_SERVER_MULTI_STATEMENTS_ON)
+
+            yield
+          ensure
+            conn.set_server_option(::Trilogy::SET_SERVER_MULTI_STATEMENTS_OFF)
+          end
+        end
+
+        def combine_multi_statements(total_sql)
+          total_sql.each_with_object([]) do |sql, total_sql_chunks|
+            previous_packet = total_sql_chunks.last
+            if max_allowed_packet_reached?(sql, previous_packet)
+              total_sql_chunks << +sql
+            else
+              previous_packet << ";\n"
+              previous_packet << sql
+            end
+          end
+        end
+
+        def max_allowed_packet_reached?(current_packet, previous_packet)
+          if current_packet.bytesize > max_allowed_packet
+            raise ActiveRecordError,
+              "Fixtures set is too large #{current_packet.bytesize}. Consider increasing the max_allowed_packet variable."
+          elsif previous_packet.nil?
+            true
+          else
+            (current_packet.bytesize + previous_packet.bytesize + 2) > max_allowed_packet
+          end
+        end
+
+        def max_allowed_packet
+          @max_allowed_packet ||= show_variable("max_allowed_packet")
+        end
+
+        def full_version
+          schema_cache.database_version.full_version_string
+        end
+
+        def get_full_version
+          with_raw_connection(allow_retry: true, uses_transaction: false) do |conn|
+            conn.server_info[:version]
+          end
+        end
+
+        def translate_exception(exception, message:, sql:, binds:)
+          error_code = exception.error_code if exception.respond_to?(:error_code)
+
+          Trilogy::LostConnectionExceptionTranslator.new(exception, message, error_code).translate || super
+        end
+
+        def default_prepared_statements
+          false
+        end
+
+        def default_insert_value(column)
+          super unless column.auto_increment?
+        end
+
+        # https://mariadb.com/kb/en/analyze-statement/
+        def analyze_without_explain?
+          mariadb? && database_version >= "10.1.0"
+        end
+    end
+  end
+end
diff --git a/activerecord/lib/active_record/migration/compatibility.rb b/activerecord/lib/active_record/migration/compatibility.rb
index ab8433ad6159d..5693fa9f03275 100644
--- a/activerecord/lib/active_record/migration/compatibility.rb
+++ b/activerecord/lib/active_record/migration/compatibility.rb
@@ -121,7 +121,7 @@ def rename_table(table_name, new_name, **options)
 
         def change_column(table_name, column_name, type, **options)
           options[:_skip_validate_options] = true
-          if connection.adapter_name == "Mysql2"
+          if connection.adapter_name == "Mysql2" || connection.adapter_name == "Trilogy"
             options[:collation] = :no_collation
           end
           super
@@ -372,7 +372,7 @@ def change_column(table_name, column_name, type, **options)
         end
 
         def create_table(table_name, **options)
-          if connection.adapter_name == "Mysql2"
+          if connection.adapter_name == "Mysql2" || connection.adapter_name == "Trilogy"
             super(table_name, options: "ENGINE=InnoDB", **options)
           else
             super
@@ -404,7 +404,7 @@ def create_table(table_name, **options)
             end
           end
 
-          unless connection.adapter_name == "Mysql2" && options[:id] == :bigint
+          unless ["Mysql2", "Trilogy"].include?(connection.adapter_name) && options[:id] == :bigint
             if [:integer, :bigint].include?(options[:id]) && !options.key?(:default)
               options[:default] = nil
             end
diff --git a/activerecord/lib/active_record/tasks/database_tasks.rb b/activerecord/lib/active_record/tasks/database_tasks.rb
index 3ab9cfe395b94..3abfa4f615e08 100644
--- a/activerecord/lib/active_record/tasks/database_tasks.rb
+++ b/activerecord/lib/active_record/tasks/database_tasks.rb
@@ -74,6 +74,7 @@ def register_task(pattern, task)
       end
 
       register_task(/mysql/,        "ActiveRecord::Tasks::MySQLDatabaseTasks")
+      register_task(/trilogy/,      "ActiveRecord::Tasks::MySQLDatabaseTasks")
       register_task(/postgresql/,   "ActiveRecord::Tasks::PostgreSQLDatabaseTasks")
       register_task(/sqlite/,       "ActiveRecord::Tasks::SQLiteDatabaseTasks")
 
diff --git a/activerecord/test/cases/adapter_test.rb b/activerecord/test/cases/adapter_test.rb
index 05a0092f759c3..6bc459ef18b4f 100644
--- a/activerecord/test/cases/adapter_test.rb
+++ b/activerecord/test/cases/adapter_test.rb
@@ -125,7 +125,7 @@ def test_exec_query_returns_an_empty_result
       assert_instance_of(ActiveRecord::Result, result)
     end
 
-    if current_adapter?(:Mysql2Adapter)
+    if current_adapter?(:Mysql2Adapter, :TrilogyAdapter)
       def test_charset
         assert_not_nil @connection.charset
         assert_not_equal "character_set_database", @connection.charset
diff --git a/activerecord/test/cases/adapters/abstract_mysql_adapter/adapter_prevent_writes_test.rb b/activerecord/test/cases/adapters/abstract_mysql_adapter/adapter_prevent_writes_test.rb
index f6ca1503c1927..12aaedde0f319 100644
--- a/activerecord/test/cases/adapters/abstract_mysql_adapter/adapter_prevent_writes_test.rb
+++ b/activerecord/test/cases/adapters/abstract_mysql_adapter/adapter_prevent_writes_test.rb
@@ -64,7 +64,7 @@ def test_doesnt_error_when_a_show_query_is_called_while_preventing_writes
 
   def test_doesnt_error_when_a_set_query_is_called_while_preventing_writes
     ActiveRecord::Base.while_preventing_writes do
-      assert_nil @conn.execute("SET NAMES utf8mb4 COLLATE utf8mb4_unicode_ci")
+      assert_nothing_raised { @conn.execute("SET NAMES utf8mb4 COLLATE utf8mb4_unicode_ci") }
     end
   end
 
@@ -91,7 +91,7 @@ def test_doesnt_error_when_a_read_query_with_leading_chars_is_called_while_preve
   def test_doesnt_error_when_a_use_query_is_called_while_preventing_writes
     ActiveRecord::Base.while_preventing_writes do
       db_name = ActiveRecord::Base.configurations.configs_for(env_name: "arunit", name: "primary").database
-      assert_nil @conn.execute("USE #{db_name}")
+      assert_nothing_raised { @conn.execute("USE #{db_name}") }
     end
   end
 
diff --git a/activerecord/test/cases/adapters/abstract_mysql_adapter/connection_test.rb b/activerecord/test/cases/adapters/abstract_mysql_adapter/connection_test.rb
index 343d4a401fe8c..523029b46ca82 100644
--- a/activerecord/test/cases/adapters/abstract_mysql_adapter/connection_test.rb
+++ b/activerecord/test/cases/adapters/abstract_mysql_adapter/connection_test.rb
@@ -24,7 +24,11 @@ def test_bad_connection
     assert_raise ActiveRecord::NoDatabaseError do
       db_config = ActiveRecord::Base.configurations.configs_for(env_name: "arunit", name: "primary")
       configuration = db_config.configuration_hash.merge(database: "inexistent_activerecord_unittest")
-      connection = ActiveRecord::Base.mysql2_connection(configuration)
+      connection = if current_adapter?(:Mysql2Adapter)
+        ActiveRecord::Base.mysql2_connection(configuration)
+      else
+        ActiveRecord::Base.trilogy_connection(configuration)
+      end
       connection.drop_table "ex", if_exists: true
     end
   end
@@ -139,17 +143,19 @@ def test_mysql_sql_mode_variable_overrides_strict_mode
     end
   end
 
-  def test_passing_arbitrary_flags_to_adapter
-    run_without_connection do |orig_connection|
-      ActiveRecord::Base.establish_connection(orig_connection.merge(flags: Mysql2::Client::COMPRESS))
-      assert_equal (Mysql2::Client::COMPRESS | Mysql2::Client::FOUND_ROWS), ActiveRecord::Base.connection.raw_connection.query_options[:flags]
+  unless current_adapter?(:TrilogyAdapter)
+    def test_passing_arbitrary_flags_to_adapter
+      run_without_connection do |orig_connection|
+        ActiveRecord::Base.establish_connection(orig_connection.merge(flags: Mysql2::Client::COMPRESS))
+        assert_equal (Mysql2::Client::COMPRESS | Mysql2::Client::FOUND_ROWS), ActiveRecord::Base.connection.raw_connection.query_options[:flags]
+      end
     end
-  end
 
-  def test_passing_flags_by_array_to_adapter
-    run_without_connection do |orig_connection|
-      ActiveRecord::Base.establish_connection(orig_connection.merge(flags: ["COMPRESS"]))
-      assert_equal ["COMPRESS", "FOUND_ROWS"], ActiveRecord::Base.connection.raw_connection.query_options[:flags]
+    def test_passing_flags_by_array_to_adapter
+      run_without_connection do |orig_connection|
+        ActiveRecord::Base.establish_connection(orig_connection.merge(flags: ["COMPRESS"]))
+        assert_equal ["COMPRESS", "FOUND_ROWS"], ActiveRecord::Base.connection.raw_connection.query_options[:flags]
+      end
     end
   end
 
diff --git a/activerecord/test/cases/adapters/trilogy/dbconsole_test.rb b/activerecord/test/cases/adapters/trilogy/dbconsole_test.rb
new file mode 100644
index 0000000000000..52b7cecf66b44
--- /dev/null
+++ b/activerecord/test/cases/adapters/trilogy/dbconsole_test.rb
@@ -0,0 +1,76 @@
+# frozen_string_literal: true
+
+require "cases/helper"
+require "active_support/testing/method_call_assertions"
+
+module ActiveRecord
+  module ConnectionAdapters
+    class TrilogyDbConsoleTest < ActiveRecord::TrilogyTestCase
+      include ActiveSupport::Testing::MethodCallAssertions
+
+      def test_trilogy
+        config = make_db_config(adapter: "trilogy", database: "db")
+
+        assert_find_cmd_and_exec_called_with([%w[mysql mysql5], "db"]) do
+          TrilogyAdapter.dbconsole(config)
+        end
+      end
+
+      def test_mysql_full
+        config = make_db_config(
+          adapter:   "trilogy",
+          database:  "db",
+          host:      "localhost",
+          port:      1234,
+          socket:    "socket",
+          username:  "user",
+          password:  "qwerty",
+          encoding:  "UTF-8",
+          sslca:     "/path/to/ca-cert.pem",
+          sslcert:   "/path/to/client-cert.pem",
+          sslcapath: "/path/to/cacerts",
+          sslcipher: "DHE-RSA-AES256-SHA",
+          sslkey:    "/path/to/client-key.pem",
+          ssl_mode:  "VERIFY_IDENTITY"
+        )
+
+        args = [
+          %w[mysql mysql5],
+          "--host=localhost",
+          "--port=1234",
+          "--socket=socket",
+          "--user=user",
+          "--default-character-set=UTF-8",
+          "--ssl-ca=/path/to/ca-cert.pem",
+          "--ssl-cert=/path/to/client-cert.pem",
+          "--ssl-capath=/path/to/cacerts",
+          "--ssl-cipher=DHE-RSA-AES256-SHA",
+          "--ssl-key=/path/to/client-key.pem",
+          "--ssl-mode=VERIFY_IDENTITY",
+          "-p", "db"
+        ]
+
+        assert_find_cmd_and_exec_called_with(args) do
+          TrilogyAdapter.dbconsole(config)
+        end
+      end
+
+      def test_mysql_include_password
+        config = make_db_config(adapter: "trilogy", database: "db", username: "user", password: "qwerty")
+
+        assert_find_cmd_and_exec_called_with([%w[mysql mysql5], "--user=user", "--password=qwerty", "db"]) do
+          TrilogyAdapter.dbconsole(config, include_password: true)
+        end
+      end
+
+      private
+        def make_db_config(config)
+          ActiveRecord::DatabaseConfigurations::HashConfig.new("test", "primary", config)
+        end
+
+        def assert_find_cmd_and_exec_called_with(args, &block)
+          assert_called_with(TrilogyAdapter, :find_cmd_and_exec, args, &block)
+        end
+    end
+  end
+end
diff --git a/activerecord/test/cases/adapters/trilogy/trilogy_adapter_test.rb b/activerecord/test/cases/adapters/trilogy/trilogy_adapter_test.rb
new file mode 100644
index 0000000000000..aaf0e8c328a02
--- /dev/null
+++ b/activerecord/test/cases/adapters/trilogy/trilogy_adapter_test.rb
@@ -0,0 +1,888 @@
+# frozen_string_literal: true
+
+require "cases/helper"
+require "support/ddl_helper"
+require "models/book"
+require "models/post"
+
+require "active_support/error_reporter/test_helper"
+
+class TrilogyAdapterTest < ActiveRecord::TrilogyTestCase
+  setup do
+    @configuration = {
+      adapter: "trilogy",
+      username: "rails",
+      database: "activerecord_unittest",
+    }
+
+    @adapter = trilogy_adapter
+    @adapter.execute("TRUNCATE books")
+    @adapter.execute("TRUNCATE posts")
+
+    db_config = ActiveRecord::DatabaseConfigurations.new({}).resolve(@configuration)
+    pool_config = ActiveRecord::ConnectionAdapters::PoolConfig.new(ActiveRecord::Base, db_config, :writing, :default)
+    @pool = ActiveRecord::ConnectionAdapters::ConnectionPool.new(pool_config)
+  end
+
+  teardown do
+    @adapter.disconnect!
+  end
+
+  test "#explain for one query" do
+    explain = @adapter.explain("select * from posts")
+    assert_match %(possible_keys), explain
+  end
+
+  test "#default_prepared_statements" do
+    assert_not_predicate @pool.connection, :prepared_statements?
+  end
+
+  test "#adapter_name answers name" do
+    assert_equal "Trilogy", @adapter.adapter_name
+  end
+
+  test "#supports_json answers true without Maria DB and greater version" do
+    assert @adapter.supports_json?
+  end
+
+  test "#supports_json answers false without Maria DB and lesser version" do
+    database_version = @adapter.class::Version.new("5.0.0", nil)
+
+    @adapter.stub(:database_version, database_version) do
+      assert_equal false, @adapter.supports_json?
+    end
+  end
+
+  test "#supports_json answers false with Maria DB" do
+    @adapter.stub(:mariadb?, true) do
+      assert_equal false, @adapter.supports_json?
+    end
+  end
+
+  test "#supports_comments? answers true" do
+    assert @adapter.supports_comments?
+  end
+
+  test "#supports_comments_in_create? answers true" do
+    assert @adapter.supports_comments_in_create?
+  end
+
+  test "#supports_savepoints? answers true" do
+    assert @adapter.supports_savepoints?
+  end
+
+  test "#requires_reloading? answers false" do
+    assert_equal false, @adapter.requires_reloading?
+  end
+
+  test "#native_database_types answers known types" do
+    assert_equal ActiveRecord::ConnectionAdapters::TrilogyAdapter::NATIVE_DATABASE_TYPES, @adapter.native_database_types
+  end
+
+  test "#quote_column_name answers quoted string when not quoted" do
+    assert_equal "`test`", @adapter.quote_column_name("test")
+  end
+
+  test "#quote_column_name answers triple quoted string when quoted" do
+    assert_equal "```test```", @adapter.quote_column_name("`test`")
+  end
+
+  test "#quote_column_name answers quoted string for integer" do
+    assert_equal "`1`", @adapter.quote_column_name(1)
+  end
+
+  test "#quote_string answers string with connection" do
+    assert_equal "\\\"test\\\"", @adapter.quote_string(%("test"))
+  end
+
+  test "#quote_string works when the connection is known to be closed" do
+    adapter = trilogy_adapter
+    adapter.connect!
+    adapter.instance_variable_get(:@raw_connection).close
+
+    assert_equal "\\\"test\\\"", adapter.quote_string(%("test"))
+  end
+
+  test "#quoted_true answers TRUE" do
+    assert_equal "TRUE", @adapter.quoted_true
+  end
+
+  test "#quoted_false answers FALSE" do
+    assert_equal "FALSE", @adapter.quoted_false
+  end
+
+  test "#active? answers true with connection" do
+    assert @adapter.active?
+  end
+
+  test "#active? answers false with connection and exception" do
+    @adapter.send(:connection).stub(:ping, -> { raise ::Trilogy::BaseError.new }) do
+      assert_equal false, @adapter.active?
+    end
+  end
+
+  test "#active? answers false without connection" do
+    adapter = trilogy_adapter
+    assert_equal false, adapter.active?
+  end
+
+  test "#reconnect closes connection with connection" do
+    connection = Minitest::Mock.new Trilogy.new(@configuration)
+    connection.expect :close, true
+    adapter = trilogy_adapter_with_connection(connection)
+    adapter.reconnect!
+
+    assert connection.verify
+  end
+
+  test "#reconnect doesn't retain old connection on failure" do
+    old_connection = Minitest::Mock.new Trilogy.new(@configuration)
+    old_connection.expect :close, true
+
+    adapter = trilogy_adapter_with_connection(old_connection)
+
+    begin
+      Trilogy.stub(:new, -> _ { raise Trilogy::BaseError.new }) do
+        adapter.reconnect!
+      end
+    rescue ActiveRecord::StatementInvalid => ex
+      assert_instance_of Trilogy::BaseError, ex.cause
+    else
+      flunk "Expected Trilogy::BaseError to be raised"
+    end
+
+    assert_nil adapter.send(:connection)
+  end
+
+  test "#reconnect answers new connection with existing connection" do
+    old_connection = @adapter.send(:connection)
+    @adapter.reconnect!
+    connection = @adapter.send(:connection)
+
+    assert_instance_of Trilogy, connection
+    assert_not_equal old_connection, connection
+  end
+
+  test "#reconnect answers new connection without existing connection" do
+    adapter = trilogy_adapter
+    adapter.reconnect!
+    assert_instance_of Trilogy, adapter.send(:connection)
+  end
+
+  test "#reset closes connection with existing connection" do
+    connection = Minitest::Mock.new Trilogy.new(@configuration)
+    connection.expect :close, true
+    adapter = trilogy_adapter_with_connection(connection)
+    adapter.reset!
+
+    assert connection.verify
+  end
+
+  test "#reset answers new connection with existing connection" do
+    old_connection = @adapter.send(:connection)
+    @adapter.reset!
+    connection = @adapter.send(:connection)
+
+    assert_instance_of Trilogy, connection
+    assert_not_equal old_connection, connection
+  end
+
+  test "#reset answers new connection without existing connection" do
+    adapter = trilogy_adapter
+    adapter.reset!
+    assert_instance_of Trilogy, adapter.send(:connection)
+  end
+
+  test "#disconnect closes connection with existing connection" do
+    connection = Minitest::Mock.new Trilogy.new(@configuration)
+    connection.expect :close, true
+    adapter = trilogy_adapter_with_connection(connection)
+    adapter.disconnect!
+
+    assert connection.verify
+  end
+
+  test "#disconnect makes adapter inactive with connection" do
+    @adapter.disconnect!
+    assert_equal false, @adapter.active?
+  end
+
+  test "#disconnect answers nil with connection" do
+    assert_nil @adapter.disconnect!
+  end
+
+  test "#disconnect answers nil without connection" do
+    adapter = trilogy_adapter
+    assert_nil adapter.disconnect!
+  end
+
+  test "#disconnect leaves adapter inactive without connection" do
+    adapter = trilogy_adapter
+    adapter.disconnect!
+
+    assert_equal false, adapter.active?
+  end
+
+  test "#discard answers nil with connection" do
+    assert_nil @adapter.discard!
+  end
+
+  test "#discard makes adapter inactive with connection" do
+    @adapter.discard!
+    assert_equal false, @adapter.active?
+  end
+
+  test "#discard answers nil without connection" do
+    adapter = trilogy_adapter
+    assert_nil adapter.discard!
+  end
+
+  test "#exec_query answers result with valid query" do
+    result = @adapter.exec_query "SELECT id, author_id, title, body FROM posts;"
+
+    assert_equal %w[id author_id title body], result.columns
+    assert_equal [], result.rows
+  end
+
+  test "#exec_query fails with invalid query" do
+    assert_raises_with_message ActiveRecord::StatementInvalid, /'activerecord_unittest.bogus' doesn't exist/ do
+      @adapter.exec_query "SELECT * FROM bogus;"
+    end
+  end
+
+  test "#exec_insert inserts new row" do
+    @adapter.exec_insert "INSERT INTO posts (title, body) VALUES ('Test', 'example');", nil, nil
+    result = @adapter.execute "SELECT id, title, body FROM posts;"
+
+    assert_equal [[1, "Test", "example"]], result.rows
+  end
+
+  test "#exec_delete deletes existing row" do
+    @adapter.execute "INSERT INTO posts (title, body) VALUES ('Test', 'example');"
+    @adapter.exec_delete "DELETE FROM posts WHERE title = 'Test';", nil, nil
+    result = @adapter.execute "SELECT id, title, body FROM posts;"
+
+    assert_equal [], result.rows
+  end
+
+  test "#exec_update updates existing row" do
+    @adapter.execute "INSERT INTO posts (title, body) VALUES ('Test', 'example');"
+    @adapter.exec_update "UPDATE posts SET title = 'Test II' where body = 'example';", nil, nil
+    result = @adapter.execute "SELECT id, title, body FROM posts;"
+
+    assert_equal [[1, "Test II", "example"]], result.rows
+  end
+
+  test "default query flags set timezone to UTC" do
+    if ActiveRecord.respond_to?(:default_timezone)
+      assert_equal :utc, ActiveRecord.default_timezone
+    else
+      assert_equal :utc, ActiveRecord::Base.default_timezone
+    end
+    ruby_time = Time.utc(2019, 5, 31, 12, 52)
+    time = "2019-05-31 12:52:00"
+
+    @adapter.execute("INSERT into books (name, format, created_at, updated_at) VALUES ('name', 'paperback', '#{time}', '#{time}');")
+    result = @adapter.execute("select * from books limit 1;")
+
+    result.each_hash do |hsh|
+      assert_equal ruby_time, hsh["created_at"]
+      assert_equal ruby_time, hsh["updated_at"]
+    end
+
+    assert_equal 1, @adapter.send(:connection).query_flags
+  end
+
+  test "query flags for timezone can be set to local" do
+    if ActiveRecord.respond_to?(:default_timezone)
+      old_timezone, ActiveRecord.default_timezone = ActiveRecord.default_timezone, :local
+      assert_equal :local, ActiveRecord.default_timezone
+    else
+      old_timezone, ActiveRecord::Base.default_timezone = ActiveRecord::Base.default_timezone, :local
+      assert_equal :local, ActiveRecord::Base.default_timezone
+    end
+    ruby_time = Time.local(2019, 5, 31, 12, 52)
+    time = "2019-05-31 12:52:00"
+
+    @adapter.execute("INSERT into books (name, format, created_at, updated_at) VALUES ('name', 'paperback', '#{time}', '#{time}');")
+    result = @adapter.execute("select * from books limit 1;")
+
+    result.each_hash do |hsh|
+      assert_equal ruby_time, hsh["created_at"]
+      assert_equal ruby_time, hsh["updated_at"]
+    end
+
+    assert_equal 5, @adapter.send(:connection).query_flags
+  ensure
+    if ActiveRecord.respond_to?(:default_timezone)
+      ActiveRecord.default_timezone = old_timezone
+    else
+      ActiveRecord::Base.default_timezone = old_timezone
+    end
+  end
+
+  test "query flags for timezone can be set to local and reset to utc" do
+    if ActiveRecord.respond_to?(:default_timezone)
+      old_timezone, ActiveRecord.default_timezone = ActiveRecord.default_timezone, :local
+      assert_equal :local, ActiveRecord.default_timezone
+    else
+      old_timezone, ActiveRecord::Base.default_timezone = ActiveRecord::Base.default_timezone, :local
+      assert_equal :local, ActiveRecord::Base.default_timezone
+    end
+    ruby_time = Time.local(2019, 5, 31, 12, 52)
+    time = "2019-05-31 12:52:00"
+
+    @adapter.execute("INSERT into books (name, format, created_at, updated_at) VALUES ('name', 'paperback', '#{time}', '#{time}');")
+    result = @adapter.execute("select * from books limit 1;")
+
+    result.each_hash do |hsh|
+      assert_equal ruby_time, hsh["created_at"]
+      assert_equal ruby_time, hsh["updated_at"]
+    end
+
+    assert_equal 5, @adapter.send(:connection).query_flags
+
+    if ActiveRecord.respond_to?(:default_timezone)
+      ActiveRecord.default_timezone = :utc
+    else
+      ActiveRecord::Base.default_timezone = :utc
+    end
+
+    ruby_utc_time = Time.utc(2019, 5, 31, 12, 52)
+    utc_result = @adapter.execute("select * from books limit 1;")
+
+    utc_result.each_hash do |hsh|
+      assert_equal ruby_utc_time, hsh["created_at"]
+      assert_equal ruby_utc_time, hsh["updated_at"]
+    end
+
+    assert_equal 1, @adapter.send(:connection).query_flags
+  ensure
+    if ActiveRecord.respond_to?(:default_timezone)
+      ActiveRecord.default_timezone = old_timezone
+    else
+      ActiveRecord::Base.default_timezone = old_timezone
+    end
+  end
+
+  test "#execute answers results for valid query" do
+    result = @adapter.execute "SELECT id, author_id, title, body FROM posts;"
+    assert_equal %w[id author_id title body], result.fields
+  end
+
+  test "#execute answers results for valid query after reconnect" do
+    mock_connection = Minitest::Mock.new Trilogy.new(@configuration)
+    adapter = trilogy_adapter_with_connection(mock_connection)
+
+    # Cause an ER_SERVER_SHUTDOWN error (code 1053) after the session is
+    # set. On reconnect, the adapter will get a real, working connection.
+    server_shutdown_error = Trilogy::ProtocolError.new
+    server_shutdown_error.instance_variable_set(:@error_code, 1053)
+    mock_connection.expect(:query, nil) { raise server_shutdown_error }
+
+    assert_raises(ActiveRecord::ConnectionFailed) do
+      adapter.execute "SELECT * FROM posts;"
+    end
+
+    adapter.reconnect!
+    result = adapter.execute "SELECT id, author_id, title, body FROM posts;"
+
+    assert_equal %w[id author_id title body], result.fields
+    assert mock_connection.verify
+    mock_connection.close
+  end
+
+  test "#execute fails with invalid query" do
+    assert_raises_with_message ActiveRecord::StatementInvalid, /Table 'activerecord_unittest.bogus' doesn't exist/ do
+      @adapter.execute "SELECT * FROM bogus;"
+    end
+  end
+
+  test "#execute fails with invalid SQL" do
+    assert_raises(ActiveRecord::StatementInvalid) do
+      @adapter.execute "SELECT bogus FROM posts;"
+    end
+  end
+
+  test "#execute answers results for valid query after losing connection unexpectedly" do
+    connection = Trilogy.new(@configuration.merge(read_timeout: 1))
+
+    adapter = trilogy_adapter_with_connection(connection)
+    assert adapter.active?
+
+    # Make connection lost for future queries by exceeding the read timeout
+    assert_raises(Trilogy::TimeoutError) do
+      connection.query "SELECT sleep(2);"
+    end
+    assert_not adapter.active?
+
+    # The adapter believes the connection is verified, so it will run the
+    # following query immediately. It will fail, and as the query's not
+    # retryable, the adapter will raise an error.
+
+    # The next query fails because the connection is lost
+    assert_raises(ActiveRecord::ConnectionFailed) do
+      adapter.execute "SELECT COUNT(*) FROM posts;"
+    end
+    assert_not adapter.active?
+
+    # The adapter now knows the connection is lost, so it will re-verify (and
+    # ultimately reconnect) before running another query.
+
+    # This query triggers a reconnect
+    result = adapter.execute "SELECT COUNT(*) FROM posts;"
+    assert_equal [[0]], result.rows
+    assert adapter.active?
+  end
+
+  test "#execute answers results for valid query after losing connection" do
+    connection = Trilogy.new(@configuration.merge(read_timeout: 1))
+
+    adapter = trilogy_adapter_with_connection(connection)
+    assert adapter.active?
+
+    # Make connection lost for future queries by exceeding the read timeout
+    assert_raises(ActiveRecord::StatementInvalid) do
+      adapter.execute "SELECT sleep(2);"
+    end
+    assert_not adapter.active?
+
+    # The above failure has not yet caused a reconnect, but the adapter has
+    # lost confidence in the connection, so it will re-verify before running
+    # the next query -- which means it will succeed.
+
+    # This query triggers a reconnect
+    result = adapter.execute "SELECT COUNT(*) FROM posts;"
+    assert_equal [[0]], result.rows
+    assert adapter.active?
+  end
+
+  test "#execute fails if the connection is closed" do
+    connection = ::Trilogy.new(@configuration.merge(read_timeout: 1))
+
+    adapter = trilogy_adapter_with_connection(connection)
+    adapter.pool = @pool
+
+    assert_raises ActiveRecord::ConnectionFailed do
+      adapter.transaction do
+        # Make connection lost for future queries by exceeding the read timeout
+        assert_raises(ActiveRecord::StatementInvalid) do
+          adapter.execute "SELECT sleep(2);"
+        end
+        assert_not adapter.active?
+
+        adapter.execute "SELECT COUNT(*) FROM posts;"
+      end
+    end
+
+    assert_not adapter.active?
+
+    # This query triggers a reconnect
+    result = adapter.execute "SELECT COUNT(*) FROM posts;"
+    assert_equal [[0]], result.rows
+  end
+
+  test "can reconnect after failing to rollback" do
+    connection = ::Trilogy.new(@configuration.merge(read_timeout: 1))
+
+    adapter = trilogy_adapter_with_connection(connection)
+    adapter.pool = @pool
+
+    adapter.transaction do
+      adapter.execute("SELECT 1")
+
+      # Cause the client to disconnect without the adapter's awareness
+      assert_raises ::Trilogy::TimeoutError do
+        adapter.send(:connection).query("SELECT sleep(2)")
+      end
+
+      raise ActiveRecord::Rollback
+    end
+
+    result = adapter.execute("SELECT 1")
+    assert_equal [[1]], result.rows
+  end
+
+  test "can reconnect after failing to commit" do
+    connection = Trilogy.new(@configuration.merge(read_timeout: 1))
+
+    adapter = trilogy_adapter_with_connection(connection)
+    adapter.pool = @pool
+
+    assert_raises ActiveRecord::ConnectionFailed do
+      adapter.transaction do
+        adapter.execute("SELECT 1")
+
+        # Cause the client to disconnect without the adapter's awareness
+        assert_raises Trilogy::TimeoutError do
+          adapter.send(:connection).query("SELECT sleep(2)")
+        end
+      end
+    end
+
+    result = adapter.execute("SELECT 1")
+    assert_equal [[1]], result.rows
+  end
+
+  test "#execute fails with deadlock error" do
+    adapter = trilogy_adapter
+
+    new_connection = Trilogy.new(@configuration)
+
+    deadlocking_adapter = trilogy_adapter_with_connection(new_connection)
+
+    # Add seed data
+    adapter.insert("INSERT INTO posts (title, body) VALUES('Setup', 'Content')")
+
+    adapter.transaction do
+      adapter.execute(
+        "UPDATE posts SET title = 'Connection 1' WHERE title != 'Connection 1';"
+      )
+
+      # Decrease the lock wait timeout in this session
+      deadlocking_adapter.execute("SET innodb_lock_wait_timeout = 1")
+
+      assert_raises(ActiveRecord::LockWaitTimeout) do
+        deadlocking_adapter.execute(
+          "UPDATE posts SET title = 'Connection 2' WHERE title != 'Connection 2';"
+        )
+      end
+    end
+  end
+
+  test "#execute fails with unknown error" do
+    assert_raises_with_message(ActiveRecord::StatementInvalid, /A random error/) do
+      connection = Minitest::Mock.new Trilogy.new(@configuration)
+      connection.expect(:query, nil) { raise Trilogy::ProtocolError, "A random error." }
+      adapter = trilogy_adapter_with_connection(connection)
+
+      adapter.execute "SELECT * FROM posts;"
+    end
+  end
+
+  test "#select_all when query cache is enabled fires the same notification payload for uncached and cached queries" do
+    @adapter.cache do
+      event_fired = false
+      subscription = ->(name, start, finish, id, payload) {
+        event_fired = true
+
+        # First, we test keys that are defined by default by the AbstractAdapter
+        assert_includes payload, :sql
+        assert_equal "SELECT * FROM posts", payload[:sql]
+
+        assert_includes payload, :name
+        assert_equal "uncached query", payload[:name]
+
+        assert_includes payload, :connection
+        assert_equal @adapter, payload[:connection]
+
+        assert_includes payload, :binds
+        assert_equal [], payload[:binds]
+
+        assert_includes payload, :type_casted_binds
+        assert_equal [], payload[:type_casted_binds]
+
+        # :stament_name is always nil and never set 🤷‍♂️
+        assert_includes payload, :statement_name
+        assert_nil payload[:statement_name]
+
+        assert_not_includes payload, :cached
+      }
+      ActiveSupport::Notifications.subscribed(subscription, "sql.active_record") do
+        @adapter.select_all "SELECT * FROM posts", "uncached query"
+      end
+      assert event_fired
+
+      event_fired = false
+      subscription = ->(name, start, finish, id, payload) {
+        event_fired = true
+
+        # First, we test keys that are defined by default by the AbstractAdapter
+        assert_includes payload, :sql
+        assert_equal "SELECT * FROM posts", payload[:sql]
+
+        assert_includes payload, :name
+        assert_equal "cached query", payload[:name]
+
+        assert_includes payload, :connection
+        assert_equal @adapter, payload[:connection]
+
+        assert_includes payload, :binds
+        assert_equal [], payload[:binds]
+
+        assert_includes payload, :type_casted_binds
+        assert_equal [], payload[:type_casted_binds].is_a?(Proc) ? payload[:type_casted_binds].call : payload[:type_casted_binds]
+
+        # Rails does not include :stament_name for cached queries 🤷‍♂️
+        assert_not_includes payload, :statement_name
+
+        assert_includes payload, :cached
+        assert_equal true, payload[:cached]
+      }
+      ActiveSupport::Notifications.subscribed(subscription, "sql.active_record") do
+        @adapter.select_all "SELECT * FROM posts", "cached query"
+      end
+      assert event_fired
+    end
+  end
+
+  test "#execute answers result with valid SQL" do
+    result = @adapter.execute "SELECT id, author_id, title FROM posts;"
+
+    assert_equal %w[id author_id title], result.fields
+    assert_equal [], result.rows
+  end
+
+  test "#execute emits a query notification" do
+    assert_notification("sql.active_record") do
+      @adapter.execute "SELECT * FROM posts;"
+    end
+  end
+
+  test "#indexes answers indexes with existing indexes" do
+    proof = [{
+      table: "posts",
+      name: "index_posts_on_author_id",
+      unique: false,
+      columns: ["author_id"],
+      lengths: {},
+      orders: {},
+      opclasses: {},
+      where: nil,
+      type: nil,
+      using: :btree,
+      comment: nil
+    }]
+
+    indexes = @adapter.indexes("posts").map do |index|
+      {
+        table: index.table,
+        name: index.name,
+        unique: index.unique,
+        columns: index.columns,
+        lengths: index.lengths,
+        orders: index.orders,
+        opclasses: index.opclasses,
+        where: index.where,
+        type: index.type,
+        using: index.using,
+        comment: index.comment
+      }
+    end
+
+    assert_equal proof, indexes
+  end
+
+  test "#indexes answers empty array with no indexes" do
+    assert_equal [], @adapter.indexes("users")
+  end
+
+  test "#begin_db_transaction answers empty result" do
+    result = @adapter.begin_db_transaction
+    assert_equal [], result.rows
+
+    # rollback transaction so it doesn't bleed into other tests
+    @adapter.rollback_db_transaction
+  end
+
+  test "#begin_db_transaction raises error" do
+    error = Class.new(Exception)
+    assert_raises error do
+      @adapter.stub(:raw_execute, -> (*) { raise error }) do
+        @adapter.begin_db_transaction
+      end
+    end
+
+    # rollback transaction so it doesn't bleed into other tests
+    @adapter.rollback_db_transaction
+  end
+
+  test "#commit_db_transaction answers empty result" do
+    result = @adapter.commit_db_transaction
+    assert_equal [], result.rows
+  end
+
+  test "#commit_db_transaction raises error" do
+    error = Class.new(Exception)
+    assert_raises error do
+      @adapter.stub(:raw_execute, -> (*) { raise error }) do
+        @adapter.commit_db_transaction
+      end
+    end
+  end
+
+  test "#rollback_db_transaction raises error" do
+    error = Class.new(Exception)
+    assert_raises error do
+      @adapter.stub(:raw_execute, -> (*) { raise error }) do
+        @adapter.rollback_db_transaction
+      end
+    end
+  end
+
+  test "#insert answers ID with ID" do
+    assert_equal 5, @adapter.insert("INSERT INTO posts (title, body) VALUES ('test', 'content');", "test", nil, 5)
+  end
+
+  test "#insert answers last ID without ID" do
+    assert_equal 1, @adapter.insert("INSERT INTO posts (title, body) VALUES ('test', 'content');", "test")
+  end
+
+  test "#insert answers incremented last ID without ID" do
+    @adapter.insert("INSERT INTO posts (title, body) VALUES ('test', 'content');", "test")
+    assert_equal 2, @adapter.insert("INSERT INTO posts (title, body) VALUES ('test', 'content');", "test")
+  end
+
+  test "#update answers affected row count when updatable" do
+    @adapter.insert("INSERT INTO posts (title, body) VALUES ('test', 'content');")
+    assert_equal 1, @adapter.update("UPDATE posts SET title = 'Test' WHERE id = 1;")
+  end
+
+  test "#update answers zero affected rows when not updatable" do
+    assert_equal 0, @adapter.update("UPDATE posts SET title = 'Test' WHERE id = 1;")
+  end
+
+  test "strict mode can be disabled" do
+    adapter = trilogy_adapter(strict: false)
+
+    adapter.execute "INSERT INTO posts (title) VALUES ('test');"
+    result = adapter.execute "SELECT * FROM posts;"
+    assert_equal [[1, nil, "test", "", nil, 0, 0, 0, 0, 0, 0, 0]], result.rows
+  end
+
+  test "#select_value returns a single value" do
+    assert_equal 123, @adapter.select_value("SELECT 123")
+  end
+
+  test "#each_hash yields symbolized result rows" do
+    @adapter.execute "INSERT INTO posts (title, body) VALUES ('test', 'content');"
+    result = @adapter.execute "SELECT title, body FROM posts;"
+
+    @adapter.each_hash(result) do |row|
+      assert_equal "test", row[:title]
+    end
+  end
+
+  test "#each_hash returns an enumarator of symbolized result rows when no block is given" do
+    @adapter.execute "INSERT INTO posts (title, body) VALUES ('test', 'content');"
+    result = @adapter.execute "SELECT * FROM posts;"
+    rows_enum = @adapter.each_hash result
+
+    assert_equal "test", rows_enum.next[:title]
+  end
+
+  test "#each_hash returns empty array when results is empty" do
+    result = @adapter.execute "SELECT * FROM posts;"
+    rows = @adapter.each_hash result
+
+    assert_empty rows.to_a
+  end
+
+  test "#error_number answers number for exception" do
+    exception = Minitest::Mock.new
+    exception.expect :error_code, 123
+
+    assert_equal 123, @adapter.error_number(exception)
+  end
+
+  # We only want to test if QueryLogs functionality is available
+  if ActiveRecord.respond_to?(:query_transformers)
+    test "execute uses AbstractAdapter#transform_query when available" do
+      # Add custom query transformer
+      old_query_transformers = ActiveRecord.query_transformers
+      ActiveRecord.query_transformers = [-> (sql, _adapter) { sql + " /* it works */" }]
+
+      sql = "SELECT * FROM posts;"
+
+      mock_connection = Minitest::Mock.new Trilogy.new(@configuration)
+      adapter = trilogy_adapter_with_connection(mock_connection)
+      mock_connection.expect :query, nil, [sql + " /* it works */"]
+
+      adapter.execute sql
+
+      assert mock_connection.verify
+    ensure
+      # Teardown custom query transformers
+      ActiveRecord.query_transformers = old_query_transformers
+    end
+  end
+
+  test "parses ssl_mode as int" do
+    adapter = trilogy_adapter(ssl_mode: 0)
+    adapter.connect!
+
+    assert adapter.active?
+  end
+
+  test "parses ssl_mode as string" do
+    adapter = trilogy_adapter(ssl_mode: "disabled")
+    adapter.connect!
+
+    assert adapter.active?
+  end
+
+  test "parses ssl_mode as string prefixed" do
+    adapter = trilogy_adapter(ssl_mode: "SSL_MODE_DISABLED")
+    adapter.connect!
+
+    assert adapter.active?
+  end
+
+  def trilogy_adapter_with_connection(connection, **config_overrides)
+    ActiveRecord::ConnectionAdapters::TrilogyAdapter
+      .new(connection, nil, {}, @configuration.merge(config_overrides))
+      .tap { |conn| conn.execute("SELECT 1") }
+  end
+
+  def trilogy_adapter(**config_overrides)
+    ActiveRecord::ConnectionAdapters::TrilogyAdapter
+      .new(@configuration.merge(config_overrides))
+  end
+
+  def assert_raises_with_message(exception, message, &block)
+    block.call
+  rescue exception => error
+    assert_match message, error.message
+  else
+    fail %(Expected #{exception} with message "#{message}" but nothing failed.)
+  end
+
+  # Create a temporary subscription to verify notification is sent.
+  # Optionally verify the notification payload includes expected types.
+  def assert_notification(notification, expected_payload = {}, &block)
+    notification_sent = false
+
+    subscription = lambda do |*args|
+      notification_sent = true
+      event = ActiveSupport::Notifications::Event.new(*args)
+
+      expected_payload.each do |key, value|
+        assert(
+          value === event.payload[key],
+          "Expected notification payload[:#{key}] to match #{value.inspect}, but got #{event.payload[key].inspect}."
+        )
+      end
+    end
+
+    ActiveSupport::Notifications.subscribed(subscription, notification) do
+      block.call if block_given?
+    end
+
+    assert notification_sent, "#{notification} notification was not sent"
+  end
+
+  # Create a temporary subscription to verify notification was not sent.
+  def assert_no_notification(notification, &block)
+    notification_sent = false
+
+    subscription = lambda do |*args|
+      notification_sent = true
+    end
+
+    ActiveSupport::Notifications.subscribed(subscription, notification) do
+      block.call if block_given?
+    end
+
+    assert_not notification_sent, "#{notification} notification was sent"
+  end
+end
diff --git a/activerecord/test/cases/associations/belongs_to_associations_test.rb b/activerecord/test/cases/associations/belongs_to_associations_test.rb
index 7a7a08c2ccd9a..928c8d5d31bd1 100644
--- a/activerecord/test/cases/associations/belongs_to_associations_test.rb
+++ b/activerecord/test/cases/associations/belongs_to_associations_test.rb
@@ -93,7 +93,7 @@ def test_belongs_to_with_primary_key
 
   def test_belongs_to_with_primary_key_joins_on_correct_column
     sql = Client.joins(:firm_with_primary_key).to_sql
-    if current_adapter?(:Mysql2Adapter)
+    if current_adapter?(:Mysql2Adapter, :TrilogyAdapter)
       assert_no_match(/`firm_with_primary_keys_companies`\.`id`/, sql)
       assert_match(/`firm_with_primary_keys_companies`\.`name`/, sql)
     elsif current_adapter?(:OracleAdapter)
diff --git a/activerecord/test/cases/associations/has_many_associations_test.rb b/activerecord/test/cases/associations/has_many_associations_test.rb
index 38d220bd9190c..7a21f3c3ccf31 100644
--- a/activerecord/test/cases/associations/has_many_associations_test.rb
+++ b/activerecord/test/cases/associations/has_many_associations_test.rb
@@ -2282,7 +2282,7 @@ def test_calling_first_nth_or_last_on_existing_record_with_build_should_load_ass
     assert_not_predicate author.topics_without_type, :loaded?
 
     assert_queries(1) do
-      if current_adapter?(:Mysql2Adapter, :SQLite3Adapter)
+      if current_adapter?(:Mysql2Adapter, :TrilogyAdapter, :SQLite3Adapter)
         assert_equal fourth, author.topics_without_type.first
         assert_equal third, author.topics_without_type.second
       end
diff --git a/activerecord/test/cases/attribute_methods_test.rb b/activerecord/test/cases/attribute_methods_test.rb
index e3125c5af6c6a..aa775a0b1f92a 100644
--- a/activerecord/test/cases/attribute_methods_test.rb
+++ b/activerecord/test/cases/attribute_methods_test.rb
@@ -193,7 +193,7 @@ def setup
     assert_equal category_attrs, category.attributes_before_type_cast
   end
 
-  if current_adapter?(:Mysql2Adapter)
+  if current_adapter?(:Mysql2Adapter, :TrilogyAdapter)
     test "read attributes_before_type_cast on a boolean" do
       bool = Boolean.create!("value" => false)
       assert_equal 0, bool.reload.attributes_before_type_cast["value"]
diff --git a/activerecord/test/cases/base_test.rb b/activerecord/test/cases/base_test.rb
index 0b03f9b765873..1850ffc022447 100644
--- a/activerecord/test/cases/base_test.rb
+++ b/activerecord/test/cases/base_test.rb
@@ -143,6 +143,7 @@ def test_column_names_are_escaped
     badchar   = {
       "SQLite3Adapter"    => '"',
       "Mysql2Adapter"     => "`",
+      "TrilogyAdapter"    => "`",
       "PostgreSQLAdapter" => '"',
       "OracleAdapter"     => '"',
     }.fetch(classname) {
@@ -878,7 +879,7 @@ def test_unicode_column_name
     assert_equal "たこ焼き仮面", weird.なまえ
   end
 
-  unless current_adapter?(:PostgreSQLAdapter)
+  unless current_adapter?(:PostgreSQLAdapter) || current_adapter?(:TrilogyAdapter)
     def test_respect_internal_encoding
       old_default_internal = Encoding.default_internal
       silence_warnings { Encoding.default_internal = "EUC-JP" }
@@ -1112,7 +1113,7 @@ def test_bignum_pk
     assert_equal company, Company.find(company.id)
   end
 
-  if current_adapter?(:PostgreSQLAdapter, :Mysql2Adapter, :SQLite3Adapter)
+  if current_adapter?(:PostgreSQLAdapter, :Mysql2Adapter, :TrilogyAdapter, :SQLite3Adapter)
     def test_default_char_types
       default = Default.new
 
@@ -1120,7 +1121,7 @@ def test_default_char_types
       assert_equal "a varchar field", default.char2
 
       # Mysql text type can't have default value
-      unless current_adapter?(:Mysql2Adapter)
+      unless current_adapter?(:Mysql2Adapter, :TrilogyAdapter)
         assert_equal "a text field", default.char3
       end
     end
diff --git a/activerecord/test/cases/cache_key_test.rb b/activerecord/test/cases/cache_key_test.rb
index 8d18a12adf79d..4e4e0bbd80e70 100644
--- a/activerecord/test/cases/cache_key_test.rb
+++ b/activerecord/test/cases/cache_key_test.rb
@@ -51,7 +51,7 @@ class CacheMeWithVersion < ActiveRecord::Base
     end
 
     test "cache_version is the same when it comes from the DB or from the user" do
-      skip("Mysql2 and PostgreSQL don't return a string value for updated_at") if current_adapter?(:Mysql2Adapter, :PostgreSQLAdapter)
+      skip("Mysql2, Trilogy, and PostgreSQL don't return a string value for updated_at") if current_adapter?(:Mysql2Adapter, :TrilogyAdapter, :PostgreSQLAdapter)
 
       record = CacheMeWithVersion.create
       record_from_db = CacheMeWithVersion.find(record.id)
@@ -63,7 +63,7 @@ class CacheMeWithVersion < ActiveRecord::Base
     end
 
     test "cache_version does not truncate zeros when timestamp ends in zeros" do
-      skip("Mysql2 and PostgreSQL don't return a string value for updated_at") if current_adapter?(:Mysql2Adapter, :PostgreSQLAdapter)
+      skip("Mysql2, Trilogy, and PostgreSQL don't return a string value for updated_at") if current_adapter?(:Mysql2Adapter, :TrilogyAdapter, :PostgreSQLAdapter)
 
       travel_to Time.now.beginning_of_day do
         record = CacheMeWithVersion.create
@@ -84,7 +84,7 @@ class CacheMeWithVersion < ActiveRecord::Base
     end
 
     test "cache_version does NOT call updated_at when value is from the database" do
-      skip("Mysql2 and PostgreSQL don't return a string value for updated_at") if current_adapter?(:Mysql2Adapter, :PostgreSQLAdapter)
+      skip("Mysql2, Trilogy, and PostgreSQL don't return a string value for updated_at") if current_adapter?(:Mysql2Adapter, :TrilogyAdapter, :PostgreSQLAdapter)
 
       record = CacheMeWithVersion.create
       record_from_db = CacheMeWithVersion.find(record.id)
diff --git a/activerecord/test/cases/calculations_test.rb b/activerecord/test/cases/calculations_test.rb
index 5660b530337f6..0fb21dce85e5b 100644
--- a/activerecord/test/cases/calculations_test.rb
+++ b/activerecord/test/cases/calculations_test.rb
@@ -400,7 +400,7 @@ def test_should_group_by_summed_field_having_condition
   end
 
   def test_should_group_by_summed_field_having_condition_from_select
-    skip unless current_adapter?(:Mysql2Adapter, :SQLite3Adapter)
+    skip unless current_adapter?(:Mysql2Adapter, :TrilogyAdapter, :SQLite3Adapter)
     c = Account.select("MIN(credit_limit) AS min_credit_limit").group(:firm_id).having("min_credit_limit > 50").sum(:credit_limit)
     assert_nil       c[1]
     assert_equal 60, c[2]
diff --git a/activerecord/test/cases/comment_test.rb b/activerecord/test/cases/comment_test.rb
index 1bea9d1dcd580..58a0243fbd9f3 100644
--- a/activerecord/test/cases/comment_test.rb
+++ b/activerecord/test/cases/comment_test.rb
@@ -182,7 +182,7 @@ def test_change_column_comment
       column = Commented.columns_hash["id"]
       assert_equal "Edited column comment", column.comment
 
-      if current_adapter?(:Mysql2Adapter)
+      if current_adapter?(:Mysql2Adapter, :TrilogyAdapter)
         assert column.auto_increment?
       end
     end
diff --git a/activerecord/test/cases/connection_adapters/mysql_type_lookup_test.rb b/activerecord/test/cases/connection_adapters/mysql_type_lookup_test.rb
index db4d197104459..14a128499d0e4 100644
--- a/activerecord/test/cases/connection_adapters/mysql_type_lookup_test.rb
+++ b/activerecord/test/cases/connection_adapters/mysql_type_lookup_test.rb
@@ -6,7 +6,7 @@
 module ActiveRecord
   module ConnectionAdapters
     class MysqlTypeLookupTest < ActiveRecord::TestCase
-      if current_adapter?(:Mysql2Adapter)
+      if current_adapter?(:Mysql2Adapter, :TrilogyAdapter)
         include ConnectionHelper
 
         setup do
diff --git a/activerecord/test/cases/connection_adapters/schema_cache_test.rb b/activerecord/test/cases/connection_adapters/schema_cache_test.rb
index 543cb9e6f4455..3fa4b5def8332 100644
--- a/activerecord/test/cases/connection_adapters/schema_cache_test.rb
+++ b/activerecord/test/cases/connection_adapters/schema_cache_test.rb
@@ -170,7 +170,7 @@ def test_caches_database_version
         assert_no_queries do
           assert_equal @database_version.to_s, @cache.database_version.to_s
 
-          if current_adapter?(:Mysql2Adapter)
+          if current_adapter?(:Mysql2Adapter, :TrilogyAdapter)
             assert_not_nil @cache.database_version.full_version_string
           end
         end
diff --git a/activerecord/test/cases/custom_locking_test.rb b/activerecord/test/cases/custom_locking_test.rb
index f52b26e9ec8b8..f5f41e75f3876 100644
--- a/activerecord/test/cases/custom_locking_test.rb
+++ b/activerecord/test/cases/custom_locking_test.rb
@@ -8,7 +8,7 @@ class CustomLockingTest < ActiveRecord::TestCase
     fixtures :people
 
     def test_custom_lock
-      if current_adapter?(:Mysql2Adapter)
+      if current_adapter?(:Mysql2Adapter, :TrilogyAdapter)
         assert_match "SHARE MODE", Person.lock("LOCK IN SHARE MODE").to_sql
         assert_sql(/LOCK IN SHARE MODE/) do
           Person.all.merge!(lock: "LOCK IN SHARE MODE").find(1)
diff --git a/activerecord/test/cases/date_time_precision_test.rb b/activerecord/test/cases/date_time_precision_test.rb
index c3fe8f9f64768..cedc2734191bf 100644
--- a/activerecord/test/cases/date_time_precision_test.rb
+++ b/activerecord/test/cases/date_time_precision_test.rb
@@ -45,7 +45,7 @@ def test_datetime_precision_is_truncated_on_assignment
       assert_equal 123456000, foo.updated_at.nsec
     end
 
-    unless current_adapter?(:Mysql2Adapter)
+    unless current_adapter?(:Mysql2Adapter, :TrilogyAdapter)
       def test_no_datetime_precision_isnt_truncated_on_assignment
         @connection.create_table(:foos, force: true)
         @connection.add_column :foos, :created_at, :datetime, precision: nil
diff --git a/activerecord/test/cases/defaults_test.rb b/activerecord/test/cases/defaults_test.rb
index 04195fe4f4a7f..948da822eee89 100644
--- a/activerecord/test/cases/defaults_test.rb
+++ b/activerecord/test/cases/defaults_test.rb
@@ -100,7 +100,7 @@ def test_default_varbinary_string
       assert_equal "varbinary_default", DefaultBinary.new.varbinary_col
     end
 
-    if current_adapter?(:Mysql2Adapter) && !ActiveRecord::Base.connection.mariadb?
+    if current_adapter?(:Mysql2Adapter, :TrilogyAdapter) && !ActiveRecord::Base.connection.mariadb?
       def test_default_binary_string
         assert_equal "binary_default", DefaultBinary.new.binary_col
       end
@@ -165,7 +165,7 @@ class PostgresqlDefaultExpressionTest < ActiveRecord::TestCase
 end
 
 class MysqlDefaultExpressionTest < ActiveRecord::TestCase
-  if current_adapter?(:Mysql2Adapter)
+  if current_adapter?(:Mysql2Adapter, :TrilogyAdapter)
     include SchemaDumpingHelper
 
     if supports_default_expression?
@@ -215,7 +215,7 @@ class MysqlDefaultExpressionTest < ActiveRecord::TestCase
 end
 
 class DefaultsTestWithoutTransactionalFixtures < ActiveRecord::TestCase
-  if current_adapter?(:Mysql2Adapter)
+  if current_adapter?(:Mysql2Adapter, :TrilogyAdapter)
     # ActiveRecord::Base#create! (and #save and other related methods) will
     # open a new transaction. When in transactional tests mode, this will
     # cause Active Record to create a new savepoint. However, since MySQL doesn't
diff --git a/activerecord/test/cases/fixtures_test.rb b/activerecord/test/cases/fixtures_test.rb
index af50e6907c855..e7a4af5eca84e 100644
--- a/activerecord/test/cases/fixtures_test.rb
+++ b/activerecord/test/cases/fixtures_test.rb
@@ -82,7 +82,7 @@ def call(_, _, _, _, values)
     end
   end
 
-  if current_adapter?(:Mysql2Adapter, :PostgreSQLAdapter)
+  if current_adapter?(:Mysql2Adapter, :TrilogyAdapter, :PostgreSQLAdapter)
     def test_bulk_insert
       subscriber = InsertQuerySubscriber.new
       subscription = ActiveSupport::Notifications.subscribe("sql.active_record", subscriber)
@@ -145,12 +145,20 @@ def test_bulk_insert_with_a_multi_statement_query_in_a_nested_transaction
     end
   end
 
-  if current_adapter?(:Mysql2Adapter)
+  if current_adapter?(:Mysql2Adapter, :TrilogyAdapter)
     def test_bulk_insert_with_multi_statements_enabled
+      orig_connection_class = ActiveRecord::Base.connection.class
       run_without_connection do |orig_connection|
-        ActiveRecord::Base.establish_connection(
-          orig_connection.merge(flags: %w[MULTI_STATEMENTS])
-        )
+        case orig_connection_class::ADAPTER_NAME
+        when "Trilogy"
+          ActiveRecord::Base.establish_connection(
+            orig_connection.merge(multi_statement: true)
+          )
+        else
+          ActiveRecord::Base.establish_connection(
+            orig_connection.merge(flags: %w[MULTI_STATEMENTS])
+          )
+        end
 
         fixtures = {
           "traffic_lights" => [
@@ -161,7 +169,12 @@ def test_bulk_insert_with_multi_statements_enabled
         assert_nothing_raised do
           conn = ActiveRecord::Base.connection
           conn.execute("SELECT 1; SELECT 2;")
-          conn.raw_connection.abandon_results!
+          case orig_connection_class::ADAPTER_NAME
+          when "Trilogy"
+            conn.raw_connection.next_result while conn.raw_connection.more_results_exist?
+          else
+            conn.raw_connection.abandon_results!
+          end
         end
 
         assert_difference "TrafficLight.count" do
@@ -176,16 +189,29 @@ def test_bulk_insert_with_multi_statements_enabled
         assert_nothing_raised do
           conn = ActiveRecord::Base.connection
           conn.execute("SELECT 1; SELECT 2;")
-          conn.raw_connection.abandon_results!
+          case orig_connection_class::ADAPTER_NAME
+          when "Trilogy"
+            conn.raw_connection.next_result while conn.raw_connection.more_results_exist?
+          else
+            conn.raw_connection.abandon_results!
+          end
         end
       end
     end
 
     def test_bulk_insert_with_multi_statements_disabled
+      orig_connection_class = ActiveRecord::Base.connection.class
       run_without_connection do |orig_connection|
-        ActiveRecord::Base.establish_connection(
-          orig_connection.merge(flags: [])
-        )
+        case orig_connection_class::ADAPTER_NAME
+        when "Trilogy"
+          ActiveRecord::Base.establish_connection(
+            orig_connection.merge(multi_statement: false)
+          )
+        else
+          ActiveRecord::Base.establish_connection(
+            orig_connection.merge(flags: [])
+          )
+        end
 
         fixtures = {
           "traffic_lights" => [
@@ -196,7 +222,12 @@ def test_bulk_insert_with_multi_statements_disabled
         assert_raises(ActiveRecord::StatementInvalid) do
           conn = ActiveRecord::Base.connection
           conn.execute("SELECT 1; SELECT 2;")
-          conn.raw_connection.abandon_results!
+          case orig_connection_class::ADAPTER_NAME
+          when "Trilogy"
+            conn.raw_connection.next_result while conn.raw_connection.more_results_exist?
+          else
+            conn.raw_connection.abandon_results!
+          end
         end
 
         assert_difference "TrafficLight.count" do
@@ -207,7 +238,12 @@ def test_bulk_insert_with_multi_statements_disabled
         assert_raises(ActiveRecord::StatementInvalid) do
           conn = ActiveRecord::Base.connection
           conn.execute("SELECT 1; SELECT 2;")
-          conn.raw_connection.abandon_results!
+          case orig_connection_class::ADAPTER_NAME
+          when "Trilogy"
+            conn.raw_connection.next_result while conn.raw_connection.more_results_exist?
+          else
+            conn.raw_connection.abandon_results!
+          end
         end
       end
     end
diff --git a/activerecord/test/cases/invalid_connection_test.rb b/activerecord/test/cases/invalid_connection_test.rb
index 51a320e048d32..02450364bdf3c 100644
--- a/activerecord/test/cases/invalid_connection_test.rb
+++ b/activerecord/test/cases/invalid_connection_test.rb
@@ -3,7 +3,7 @@
 require "cases/helper"
 
 class TestAdapterWithInvalidConnection < ActiveRecord::TestCase
-  if current_adapter?(:Mysql2Adapter)
+  if current_adapter?(:Mysql2Adapter, :TrilogyAdapter)
     self.use_transactional_tests = false
 
     class Bird < ActiveRecord::Base
diff --git a/activerecord/test/cases/invertible_migration_test.rb b/activerecord/test/cases/invertible_migration_test.rb
index f97727e590feb..11507518d0296 100644
--- a/activerecord/test/cases/invertible_migration_test.rb
+++ b/activerecord/test/cases/invertible_migration_test.rb
@@ -478,7 +478,7 @@ def test_migrations_can_handle_foreign_keys_to_specific_tables
     end
 
     # MySQL 5.7 and Oracle do not allow to create duplicate indexes on the same columns
-    unless current_adapter?(:Mysql2Adapter, :OracleAdapter)
+    unless current_adapter?(:Mysql2Adapter, :TrilogyAdapter, :OracleAdapter)
       def test_migrate_revert_add_index_with_name
         RevertNamedIndexMigration1.new.migrate(:up)
         RevertNamedIndexMigration2.new.migrate(:up)
diff --git a/activerecord/test/cases/migration/change_schema_test.rb b/activerecord/test/cases/migration/change_schema_test.rb
index 2f047d638e8df..6e50f481d0782 100644
--- a/activerecord/test/cases/migration/change_schema_test.rb
+++ b/activerecord/test/cases/migration/change_schema_test.rb
@@ -52,7 +52,7 @@ def test_create_table_with_not_null_column
 
       def test_create_table_with_defaults
         # MySQL doesn't allow defaults on TEXT or BLOB columns.
-        mysql = current_adapter?(:Mysql2Adapter)
+        mysql = current_adapter?(:Mysql2Adapter, :TrilogyAdapter)
 
         connection.create_table :testings do |t|
           t.column :one, :string, default: "hello"
@@ -143,7 +143,7 @@ def test_create_table_with_limits
           assert_equal "smallint", one.sql_type
           assert_equal "integer", four.sql_type
           assert_equal "bigint", eight.sql_type
-        elsif current_adapter?(:Mysql2Adapter)
+        elsif current_adapter?(:Mysql2Adapter, :TrilogyAdapter)
           assert_match %r/\Aint/, default.sql_type
           assert_match %r/\Atinyint/, one.sql_type
           assert_match %r/\Aint/, four.sql_type
@@ -281,7 +281,7 @@ def test_add_column_with_timestamp_type
 
         if current_adapter?(:PostgreSQLAdapter)
           assert_equal "timestamp without time zone", column.sql_type
-        elsif current_adapter?(:Mysql2Adapter)
+        elsif current_adapter?(:Mysql2Adapter, :TrilogyAdapter)
           assert_equal "timestamp", column.sql_type
         elsif current_adapter?(:OracleAdapter)
           assert_equal "TIMESTAMP(6)", column.sql_type
@@ -301,7 +301,7 @@ def test_add_column_with_postgresql_datetime_type
 
         if current_adapter?(:PostgreSQLAdapter)
           assert_equal "timestamp(6) without time zone", column.sql_type
-        elsif current_adapter?(:Mysql2Adapter)
+        elsif current_adapter?(:Mysql2Adapter, :TrilogyAdapter)
           sql_type = supports_datetime_with_precision? ? "datetime(6)" : "datetime"
           assert_equal sql_type, column.sql_type
         else
@@ -337,7 +337,7 @@ def test_change_column_with_timestamp_type
 
         if current_adapter?(:PostgreSQLAdapter)
           assert_equal "timestamp without time zone", column.sql_type
-        elsif current_adapter?(:Mysql2Adapter)
+        elsif current_adapter?(:Mysql2Adapter, :TrilogyAdapter)
           assert_equal "timestamp", column.sql_type
         elsif current_adapter?(:OracleAdapter)
           assert_equal "TIMESTAMP(6)", column.sql_type
@@ -518,7 +518,7 @@ class ChangeSchemaWithDependentObjectsTest < ActiveRecord::TestCase
         end
 
         def test_create_table_with_force_cascade_drops_dependent_objects
-          if current_adapter?(:Mysql2Adapter)
+          if current_adapter?(:Mysql2Adapter, :TrilogyAdapter)
             skip "MySQL > 5.5 does not drop dependent objects with DROP TABLE CASCADE"
           elsif current_adapter?(:SQLite3Adapter)
             skip "SQLite3 does not support DROP TABLE CASCADE syntax"
diff --git a/activerecord/test/cases/migration/check_constraint_test.rb b/activerecord/test/cases/migration/check_constraint_test.rb
index 5ac1500990208..4bbf4ffce8a82 100644
--- a/activerecord/test/cases/migration/check_constraint_test.rb
+++ b/activerecord/test/cases/migration/check_constraint_test.rb
@@ -48,7 +48,7 @@ def test_check_constraints
           assert_equal "products", constraint.table_name
           assert_equal "products_price_check", constraint.name
 
-          if current_adapter?(:Mysql2Adapter)
+          if current_adapter?(:Mysql2Adapter, :TrilogyAdapter)
             assert_equal "`price` > `discounted_price`", constraint.expression
           else
             assert_equal "price > discounted_price", constraint.expression
@@ -116,7 +116,7 @@ def test_add_check_constraint
           assert_equal "trades", constraint.table_name
           assert_equal "chk_rails_2189e9f96c", constraint.name
 
-          if current_adapter?(:Mysql2Adapter)
+          if current_adapter?(:Mysql2Adapter, :TrilogyAdapter)
             assert_equal "`quantity` > 0", constraint.expression
           else
             assert_equal "quantity > 0", constraint.expression
@@ -246,7 +246,7 @@ def test_remove_check_constraint
           assert_equal "trades", constraint.table_name
           assert_equal "price_check", constraint.name
 
-          if current_adapter?(:Mysql2Adapter)
+          if current_adapter?(:Mysql2Adapter, :TrilogyAdapter)
             assert_equal "`price` > 0", constraint.expression
           else
             assert_equal "price > 0", constraint.expression
diff --git a/activerecord/test/cases/migration/column_attributes_test.rb b/activerecord/test/cases/migration/column_attributes_test.rb
index b6064500ee04d..d52c143cd9c0f 100644
--- a/activerecord/test/cases/migration/column_attributes_test.rb
+++ b/activerecord/test/cases/migration/column_attributes_test.rb
@@ -39,13 +39,13 @@ def test_add_remove_single_field_using_symbol_arguments
 
       def test_add_column_without_limit
         # TODO: limit: nil should work with all adapters.
-        skip "MySQL wrongly enforces a limit of 255" if current_adapter?(:Mysql2Adapter)
+        skip "MySQL wrongly enforces a limit of 255" if current_adapter?(:Mysql2Adapter, :TrilogyAdapter)
         add_column :test_models, :description, :string, limit: nil
         TestModel.reset_column_information
         assert_nil TestModel.columns_hash["description"].limit
       end
 
-      if current_adapter?(:Mysql2Adapter, :PostgreSQLAdapter)
+      if current_adapter?(:Mysql2Adapter, :TrilogyAdapter, :PostgreSQLAdapter)
         def test_unabstracted_database_dependent_types
           add_column :test_models, :intelligence_quotient, :smallint
           TestModel.reset_column_information
@@ -174,7 +174,7 @@ def test_native_types
         end
       end
 
-      if current_adapter?(:Mysql2Adapter, :PostgreSQLAdapter)
+      if current_adapter?(:Mysql2Adapter, :TrilogyAdapter, :PostgreSQLAdapter)
         def test_out_of_range_limit_should_raise
           assert_raise(ArgumentError) { add_column :test_models, :integer_too_big, :integer, limit: 10 }
           assert_raise(ArgumentError) { add_column :test_models, :text_too_big, :text, limit: 0xfffffffff }
diff --git a/activerecord/test/cases/migration/column_positioning_test.rb b/activerecord/test/cases/migration/column_positioning_test.rb
index 1c62a68cf9cbd..5bec98860acf9 100644
--- a/activerecord/test/cases/migration/column_positioning_test.rb
+++ b/activerecord/test/cases/migration/column_positioning_test.rb
@@ -25,7 +25,7 @@ def setup
         ActiveRecord::Base.primary_key_prefix_type = nil
       end
 
-      if current_adapter?(:Mysql2Adapter)
+      if current_adapter?(:Mysql2Adapter, :TrilogyAdapter)
         def test_column_positioning
           assert_equal %w(first second third), conn.columns(:testings).map(&:name)
         end
diff --git a/activerecord/test/cases/migration/columns_test.rb b/activerecord/test/cases/migration/columns_test.rb
index 4cd88754ef728..784c95d3a0845 100644
--- a/activerecord/test/cases/migration/columns_test.rb
+++ b/activerecord/test/cases/migration/columns_test.rb
@@ -64,7 +64,7 @@ def test_rename_column_preserves_default_value_not_null
         assert_equal "70000", default_after
       end
 
-      if current_adapter?(:Mysql2Adapter)
+      if current_adapter?(:Mysql2Adapter, :TrilogyAdapter)
         def test_mysql_rename_column_preserves_auto_increment
           rename_column "test_models", "id", "id_test"
           assert_predicate connection.columns("test_models").find { |c| c.name == "id_test" }, :auto_increment?
@@ -136,7 +136,7 @@ def test_remove_column_with_index
       def test_remove_column_with_multi_column_index
         # MariaDB starting with 10.2.8
         # Dropping a column that is part of a multi-column UNIQUE constraint is not permitted.
-        skip if current_adapter?(:Mysql2Adapter) && connection.mariadb? && connection.database_version >= "10.2.8"
+        skip if current_adapter?(:Mysql2Adapter, :TrilogyAdapter) && connection.mariadb? && connection.database_version >= "10.2.8"
 
         add_column "test_models", :hat_size, :integer
         add_column "test_models", :hat_style, :string, limit: 100
diff --git a/activerecord/test/cases/migration/compatibility_test.rb b/activerecord/test/cases/migration/compatibility_test.rb
index 5ab2b0d470671..f20168d404721 100644
--- a/activerecord/test/cases/migration/compatibility_test.rb
+++ b/activerecord/test/cases/migration/compatibility_test.rb
@@ -646,7 +646,7 @@ def migrate(x)
           end
         }.new
 
-        if current_adapter?(:Mysql2Adapter)
+        if current_adapter?(:Mysql2Adapter, :TrilogyAdapter)
           # MySQL does not allow to create table names longer than limit
           error = assert_raises(StandardError) do
             ActiveRecord::Migrator.new(:up, [migration], @schema_migration, @internal_metadata).migrate
@@ -676,7 +676,7 @@ def migrate(x)
           end
         }.new
 
-        if current_adapter?(:Mysql2Adapter)
+        if current_adapter?(:Mysql2Adapter, :TrilogyAdapter)
           # MySQL does not allow to create table names longer than limit
           error = assert_raises(StandardError) do
             ActiveRecord::Migrator.new(:up, [migration], @schema_migration, @internal_metadata).migrate
@@ -758,7 +758,7 @@ def up
         end
       end
 
-      if current_adapter?(:Mysql2Adapter)
+      if current_adapter?(:Mysql2Adapter, :TrilogyAdapter)
         def test_change_column_on_7_0
           migration = Class.new(ActiveRecord::Migration[7.0]) do
             def up
@@ -774,7 +774,7 @@ def up
 
       private
         def precision_implicit_default
-          if current_adapter?(:Mysql2Adapter)
+          if current_adapter?(:Mysql2Adapter, :TrilogyAdapter)
             { precision: 0 }
           else
             { precision: nil }
@@ -1054,7 +1054,7 @@ def change
       assert_match %r{bigint "banana_id", null: false}, schema
     end
 
-    if current_adapter?(:Mysql2Adapter)
+    if current_adapter?(:Mysql2Adapter, :TrilogyAdapter)
       def test_legacy_bigint_primary_key_should_be_auto_incremented
         @migration = Class.new(migration_class) {
           def change
@@ -1101,7 +1101,7 @@ def assert_legacy_primary_key
         assert_not_predicate legacy_pk, :bigint?
         assert_not legacy_pk.null
 
-        if current_adapter?(:Mysql2Adapter, :PostgreSQLAdapter)
+        if current_adapter?(:Mysql2Adapter, :TrilogyAdapter, :PostgreSQLAdapter)
           schema = dump_table_schema "legacy_primary_keys"
           assert_match %r{create_table "legacy_primary_keys", id: :(?:integer|serial), (?!default: nil)}, schema
         end
diff --git a/activerecord/test/cases/migration/foreign_key_test.rb b/activerecord/test/cases/migration/foreign_key_test.rb
index cd64df50606f5..15817382c2ea5 100644
--- a/activerecord/test/cases/migration/foreign_key_test.rb
+++ b/activerecord/test/cases/migration/foreign_key_test.rb
@@ -93,7 +93,7 @@ def test_rename_column_of_child_table
         end
 
         def test_rename_reference_column_of_child_table
-          if current_adapter?(:Mysql2Adapter) && !@connection.send(:supports_rename_index?)
+          if current_adapter?(:Mysql2Adapter, :TrilogyAdapter) && !@connection.send(:supports_rename_index?)
             skip "Cannot drop index, needed in a foreign key constraint"
           end
 
@@ -271,7 +271,7 @@ def test_add_on_delete_restrict_foreign_key
           assert_equal 1, foreign_keys.size
 
           fk = foreign_keys.first
-          if current_adapter?(:Mysql2Adapter)
+          if current_adapter?(:Mysql2Adapter, :TrilogyAdapter)
             # ON DELETE RESTRICT is the default on MySQL
             assert_nil fk.on_delete
           else
@@ -748,7 +748,7 @@ def test_add_foreign_key_with_if_not_exists_not_set
               @connection.add_foreign_key :astronauts, :rockets
             end
 
-            if current_adapter?(:Mysql2Adapter)
+            if current_adapter?(:Mysql2Adapter, :TrilogyAdapter)
               if ActiveRecord::Base.connection.mariadb?
                 assert_match(/Duplicate key on write or update/, error.message)
               elsif ActiveRecord::Base.connection.database_version < "5.6"
diff --git a/activerecord/test/cases/migration/index_test.rb b/activerecord/test/cases/migration/index_test.rb
index 0733140a69f1b..e23665d5fcd69 100644
--- a/activerecord/test/cases/migration/index_test.rb
+++ b/activerecord/test/cases/migration/index_test.rb
@@ -255,7 +255,7 @@ def test_add_index
         connection.remove_index("testings", name: "named_admin")
 
         # Selected adapters support index sort order
-        if current_adapter?(:SQLite3Adapter, :Mysql2Adapter, :PostgreSQLAdapter)
+        if current_adapter?(:SQLite3Adapter, :Mysql2Adapter, :TrilogyAdapter, :PostgreSQLAdapter)
           connection.add_index("testings", ["last_name"], order: { last_name: :desc })
           connection.remove_index("testings", ["last_name"])
           connection.add_index("testings", ["last_name", "first_name"], order: { last_name: :desc })
diff --git a/activerecord/test/cases/migration/invalid_options_test.rb b/activerecord/test/cases/migration/invalid_options_test.rb
index 1f509ff549a92..2ae37887d5bb3 100644
--- a/activerecord/test/cases/migration/invalid_options_test.rb
+++ b/activerecord/test/cases/migration/invalid_options_test.rb
@@ -10,7 +10,7 @@ class InvalidOptionsTest < ActiveRecord::TestCase
       def invalid_add_column_option_exception_message(key)
         default_keys = [":limit", ":precision", ":scale", ":default", ":null", ":collation", ":comment", ":primary_key", ":if_exists", ":if_not_exists"]
 
-        if current_adapter?(:Mysql2Adapter)
+        if current_adapter?(:Mysql2Adapter, :TrilogyAdapter)
           default_keys.concat([":auto_increment", ":charset", ":as", ":size", ":unsigned", ":first", ":after", ":type", ":stored"])
         elsif current_adapter?(:PostgreSQLAdapter)
           default_keys.concat([":array", ":using", ":cast_as", ":as", ":type", ":enum_type", ":stored"])
@@ -27,7 +27,7 @@ def invalid_create_table_option_exception_message(key)
         table_keys = [":temporary", ":if_not_exists", ":options", ":as", ":comment", ":charset", ":collation"]
         primary_keys = [":limit", ":default", ":precision"]
 
-        if current_adapter?(:Mysql2Adapter)
+        if current_adapter?(:Mysql2Adapter, :TrilogyAdapter)
           primary_keys.concat([":unsigned"])
         elsif current_adapter?(:SQLite3Adapter)
           table_keys.concat([":rename"])
@@ -95,7 +95,7 @@ def test_add_index_with_invalid_options
         )
       end
 
-      if current_adapter?(:Mysql2Adapter) || current_adapter?(:PostgreSQLAdapter)
+      if current_adapter?(:Mysql2Adapter, :TrilogyAdapter, :PostgreSQLAdapter)
         def test_change_column_with_invalid_options
           exception = assert_raises(ArgumentError) do
             change_column "posts", "title", :text, liimit: true
diff --git a/activerecord/test/cases/migration/schema_definitions_test.rb b/activerecord/test/cases/migration/schema_definitions_test.rb
index dee7d508eb443..57ee9fabdbc7f 100644
--- a/activerecord/test/cases/migration/schema_definitions_test.rb
+++ b/activerecord/test/cases/migration/schema_definitions_test.rb
@@ -63,7 +63,7 @@ def test_build_create_index_definition
         connection.drop_table(:test) if connection.table_exists?(:test)
       end
 
-      if current_adapter?(:Mysql2Adapter)
+      if current_adapter?(:Mysql2Adapter, :TrilogyAdapter)
         def test_build_create_index_definition_for_existing_index
           connection.create_table(:test) do |t|
             t.column :foo, :string
diff --git a/activerecord/test/cases/migration_test.rb b/activerecord/test/cases/migration_test.rb
index f2b6af005b66b..971acf15b2e8d 100644
--- a/activerecord/test/cases/migration_test.rb
+++ b/activerecord/test/cases/migration_test.rb
@@ -284,7 +284,7 @@ def migrate(x)
         migrator.migrate
       end
 
-      if current_adapter?(:Mysql2Adapter)
+      if current_adapter?(:Mysql2Adapter, :TrilogyAdapter)
         if ActiveRecord::Base.connection.mariadb?
           assert_match(/Can't DROP COLUMN `last_name`; check that it exists/, error.message)
         else
@@ -958,7 +958,7 @@ def test_decimal_scale_without_precision_should_raise
     Person.connection.drop_table :test_decimal_scales, if_exists: true
   end
 
-  if current_adapter?(:Mysql2Adapter, :PostgreSQLAdapter)
+  if current_adapter?(:Mysql2Adapter, :TrilogyAdapter, :PostgreSQLAdapter)
     def test_out_of_range_integer_limit_should_raise
       e = assert_raise(ArgumentError) do
         Person.connection.create_table :test_integer_limits, force: true do |t|
@@ -996,7 +996,7 @@ def test_out_of_range_binary_limit_should_raise
     end
   end
 
-  if current_adapter?(:Mysql2Adapter)
+  if current_adapter?(:Mysql2Adapter, :TrilogyAdapter)
     def test_invalid_text_size_should_raise
       e = assert_raise(ArgumentError) do
         Person.connection.create_table :test_text_sizes, force: true do |t|
@@ -1232,6 +1232,7 @@ def test_adding_multiple_columns
       classname = ActiveRecord::Base.connection.class.name[/[^:]*$/]
       expected_query_count = {
         "Mysql2Adapter"     => 1,
+        "TrilogyAdapter"    => 1,
         "PostgreSQLAdapter" => 2, # one for bulk change, one for comment
       }.fetch(classname) {
         raise "need an expected query count for #{classname}"
@@ -1334,6 +1335,7 @@ def test_adding_indexes
       classname = ActiveRecord::Base.connection.class.name[/[^:]*$/]
       expected_query_count = {
         "Mysql2Adapter"     => 1, # mysql2 supports creating two indexes using one statement
+        "TrilogyAdapter"    => 1, # trilogy supports creating two indexes using one statement
         "PostgreSQLAdapter" => 3,
       }.fetch(classname) {
         raise "need an expected query count for #{classname}"
@@ -1367,6 +1369,7 @@ def test_removing_index
       classname = ActiveRecord::Base.connection.class.name[/[^:]*$/]
       expected_query_count = {
         "Mysql2Adapter"     => 1, # mysql2 supports dropping and creating two indexes using one statement
+        "TrilogyAdapter"    => 1, # trilogy supports dropping and creating two indexes using one statement
         "PostgreSQLAdapter" => 2,
       }.fetch(classname) {
         raise "need an expected query count for #{classname}"
@@ -1397,6 +1400,7 @@ def test_changing_columns
       classname = ActiveRecord::Base.connection.class.name[/[^:]*$/]
       expected_query_count = {
         "Mysql2Adapter"     => 3, # one query for columns, one query for primary key, one query to do the bulk change
+        "TrilogyAdapter"    => 3, # one query for columns, one query for primary key, one query to do the bulk change
         "PostgreSQLAdapter" => 3, # one query for columns, one for bulk change, one for comment
       }.fetch(classname) {
         raise "need an expected query count for #{classname}"
@@ -1427,6 +1431,7 @@ def test_changing_column_null_with_default
       classname = ActiveRecord::Base.connection.class.name[/[^:]*$/]
       expected_query_count = {
         "Mysql2Adapter"     => 7, # four queries to retrieve schema info, one for bulk change, one for UPDATE, one for NOT NULL
+        "TrilogyAdapter"    => 7, # four queries to retrieve schema info, one for bulk change, one for UPDATE, one for NOT NULL
         "PostgreSQLAdapter" => 5, # two queries for columns, one for bulk change, one for UPDATE, one for NOT NULL
       }.fetch(classname) {
         raise "need an expected query count for #{classname}"
@@ -1471,7 +1476,7 @@ def test_default_functions_on_columns
       end
     end
 
-    if current_adapter?(:Mysql2Adapter)
+    if current_adapter?(:Mysql2Adapter, :TrilogyAdapter)
       def test_updating_auto_increment
         with_bulk_change_table do |t|
           t.change :id, :bigint, auto_increment: true
@@ -1498,6 +1503,7 @@ def test_changing_index
       classname = ActiveRecord::Base.connection.class.name[/[^:]*$/]
       expected_query_count = {
         "Mysql2Adapter"     => 1, # mysql2 supports dropping and creating two indexes using one statement
+        "TrilogyAdapter"    => 1, # trilogy supports dropping and creating two indexes using one statement
         "PostgreSQLAdapter" => 2,
       }.fetch(classname) {
         raise "need an expected query count for #{classname}"
diff --git a/activerecord/test/cases/primary_keys_test.rb b/activerecord/test/cases/primary_keys_test.rb
index 03851abc2e5da..09e4061391725 100644
--- a/activerecord/test/cases/primary_keys_test.rb
+++ b/activerecord/test/cases/primary_keys_test.rb
@@ -342,7 +342,7 @@ def test_any_type_primary_key
     assert_no_match %r{t\.index \["code"\]}, schema
   end
 
-  if current_adapter?(:Mysql2Adapter) && supports_datetime_with_precision?
+  if current_adapter?(:Mysql2Adapter, :TrilogyAdapter) && supports_datetime_with_precision?
     test "schema typed primary key column" do
       @connection.create_table(:scheduled_logs, id: :timestamp, precision: 6, force: true)
       schema = dump_table_schema("scheduled_logs")
@@ -483,7 +483,7 @@ def test_schema_dump_primary_key_bigint_with_default_nil
 end
 
 class PrimaryKeyIntegerTest < ActiveRecord::TestCase
-  if current_adapter?(:PostgreSQLAdapter, :Mysql2Adapter)
+  if current_adapter?(:PostgreSQLAdapter, :Mysql2Adapter, :TrilogyAdapter)
     include SchemaDumpingHelper
 
     self.use_transactional_tests = false
@@ -519,7 +519,7 @@ class Widget < ActiveRecord::Base
       assert_match %r{create_table "widgets", id: :#{@pk_type}, }, schema
     end
 
-    if current_adapter?(:Mysql2Adapter)
+    if current_adapter?(:Mysql2Adapter, :TrilogyAdapter)
       test "primary key column type with options" do
         @connection.create_table(:widgets, id: :primary_key, limit: 4, unsigned: true, force: true)
         column = @connection.columns(:widgets).find { |c| c.name == "id" }
diff --git a/activerecord/test/cases/quoting_test.rb b/activerecord/test/cases/quoting_test.rb
index 9b72b7c402859..6d9cc8d68e432 100644
--- a/activerecord/test/cases/quoting_test.rb
+++ b/activerecord/test/cases/quoting_test.rb
@@ -207,7 +207,7 @@ def test_type_cast_symbol
 
       def test_type_cast_date
         date = Date.today
-        if current_adapter?(:Mysql2Adapter)
+        if current_adapter?(:Mysql2Adapter, :TrilogyAdapter)
           expected = date
         else
           expected = @conn.quoted_date(date)
@@ -217,7 +217,7 @@ def test_type_cast_date
 
       def test_type_cast_time
         time = Time.now
-        if current_adapter?(:Mysql2Adapter)
+        if current_adapter?(:Mysql2Adapter, :TrilogyAdapter)
           expected = time
         else
           expected = @conn.quoted_date(time)
diff --git a/activerecord/test/cases/relation/delete_all_test.rb b/activerecord/test/cases/relation/delete_all_test.rb
index 022a2d10be849..e449a967feeb2 100644
--- a/activerecord/test/cases/relation/delete_all_test.rb
+++ b/activerecord/test/cases/relation/delete_all_test.rb
@@ -81,7 +81,7 @@ def test_delete_all_with_joins_and_where_part_is_hash
       assert_equal pets.count, pets.delete_all
     end
 
-    if current_adapter?(:Mysql2Adapter)
+    if current_adapter?(:Mysql2Adapter, :TrilogyAdapter)
       assert_no_match %r/SELECT DISTINCT #{Regexp.escape(Pet.connection.quote_table_name("pets.pet_id"))}/, sqls.last
     else
       assert_match %r/SELECT #{Regexp.escape(Pet.connection.quote_table_name("pets.pet_id"))}/, sqls.last
diff --git a/activerecord/test/cases/relation/merging_test.rb b/activerecord/test/cases/relation/merging_test.rb
index bd5e200149651..751748d6db68b 100644
--- a/activerecord/test/cases/relation/merging_test.rb
+++ b/activerecord/test/cases/relation/merging_test.rb
@@ -168,7 +168,7 @@ def test_merge_doesnt_duplicate_same_clauses
 
     only_david = Author.where("#{author_id} IN (?)", david)
 
-    if current_adapter?(:Mysql2Adapter)
+    if current_adapter?(:Mysql2Adapter, :TrilogyAdapter)
       assert_sql(/WHERE \(#{Regexp.escape(author_id)} IN \('1'\)\)\z/) do
         assert_equal [david], only_david.merge(only_david)
       end
diff --git a/activerecord/test/cases/relation/update_all_test.rb b/activerecord/test/cases/relation/update_all_test.rb
index 583c3090a3ae7..f1db13a190d7d 100644
--- a/activerecord/test/cases/relation/update_all_test.rb
+++ b/activerecord/test/cases/relation/update_all_test.rb
@@ -66,7 +66,7 @@ def test_update_all_with_joins
       assert_equal pets.count, pets.update_all(name: "Bob")
     end
 
-    if current_adapter?(:Mysql2Adapter)
+    if current_adapter?(:Mysql2Adapter, :TrilogyAdapter)
       assert_no_match %r/SELECT DISTINCT #{Regexp.escape(Pet.connection.quote_table_name("pets.pet_id"))}/, sqls.last
     else
       assert_match %r/SELECT #{Regexp.escape(Pet.connection.quote_table_name("pets.pet_id"))}/, sqls.last
diff --git a/activerecord/test/cases/relations_test.rb b/activerecord/test/cases/relations_test.rb
index c77b0786f4ad6..8b210df44b6e6 100644
--- a/activerecord/test/cases/relations_test.rb
+++ b/activerecord/test/cases/relations_test.rb
@@ -475,7 +475,7 @@ def test_finding_with_complex_order
 
   def test_finding_with_sanitized_order
     query = Tag.order([Arel.sql("field(id, ?)"), [1, 3, 2]]).to_sql
-    if current_adapter?(:Mysql2Adapter)
+    if current_adapter?(:Mysql2Adapter, :TrilogyAdapter)
       assert_match(/field\(id, '1','3','2'\)/, query)
     else
       assert_match(/field\(id, 1,3,2\)/, query)
@@ -490,7 +490,7 @@ def test_finding_with_sanitized_order
 
   def test_finding_with_arel_sql_order
     query = Tag.order(Arel.sql("field(id, ?)", [1, 3, 2])).to_sql
-    if current_adapter?(:Mysql2Adapter)
+    if current_adapter?(:Mysql2Adapter, :TrilogyAdapter)
       assert_match(/field\(id, '1', '3', '2'\)/, query)
     else
       assert_match(/field\(id, 1, 3, 2\)/, query)
diff --git a/activerecord/test/cases/sanitize_test.rb b/activerecord/test/cases/sanitize_test.rb
index 1075e8b1c0e2f..cb32141c9f790 100644
--- a/activerecord/test/cases/sanitize_test.rb
+++ b/activerecord/test/cases/sanitize_test.rb
@@ -31,7 +31,7 @@ def test_sanitize_sql_array_handles_bind_variables
   def test_sanitize_sql_array_handles_named_bind_variables
     quoted_bambi = ActiveRecord::Base.connection.quote("Bambi")
     assert_equal "name=#{quoted_bambi}", Binary.sanitize_sql_array(["name=:name", name: "Bambi"])
-    if current_adapter?(:Mysql2Adapter)
+    if current_adapter?(:Mysql2Adapter, :TrilogyAdapter)
       assert_equal "name=#{quoted_bambi} AND id='1'", Binary.sanitize_sql_array(["name=:name AND id=:id", name: "Bambi", id: 1])
     else
       assert_equal "name=#{quoted_bambi} AND id=1", Binary.sanitize_sql_array(["name=:name AND id=:id", name: "Bambi", id: 1])
@@ -118,7 +118,7 @@ def test_bind_arity
   end
 
   def test_named_bind_variables
-    if current_adapter?(:Mysql2Adapter)
+    if current_adapter?(:Mysql2Adapter, :TrilogyAdapter)
       assert_equal "'1'", bind(":a", a: 1) # ' ruby-mode
       assert_equal "'1' '1'", bind(":a :a", a: 1)  # ' ruby-mode
     else
@@ -150,28 +150,28 @@ def each(&b)
   def test_bind_enumerable
     quoted_abc = %(#{ActiveRecord::Base.connection.quote('a')},#{ActiveRecord::Base.connection.quote('b')},#{ActiveRecord::Base.connection.quote('c')})
 
-    if current_adapter?(:Mysql2Adapter)
+    if current_adapter?(:Mysql2Adapter, :TrilogyAdapter)
       assert_equal "'1','2','3'", bind("?", [1, 2, 3])
     else
       assert_equal "1,2,3", bind("?", [1, 2, 3])
     end
     assert_equal quoted_abc, bind("?", %w(a b c))
 
-    if current_adapter?(:Mysql2Adapter)
+    if current_adapter?(:Mysql2Adapter, :TrilogyAdapter)
       assert_equal "'1','2','3'", bind(":a", a: [1, 2, 3])
     else
       assert_equal "1,2,3", bind(":a", a: [1, 2, 3])
     end
     assert_equal quoted_abc, bind(":a", a: %w(a b c)) # '
 
-    if current_adapter?(:Mysql2Adapter)
+    if current_adapter?(:Mysql2Adapter, :TrilogyAdapter)
       assert_equal "'1','2','3'", bind("?", SimpleEnumerable.new([1, 2, 3]))
     else
       assert_equal "1,2,3", bind("?", SimpleEnumerable.new([1, 2, 3]))
     end
     assert_equal quoted_abc, bind("?", SimpleEnumerable.new(%w(a b c)))
 
-    if current_adapter?(:Mysql2Adapter)
+    if current_adapter?(:Mysql2Adapter, :TrilogyAdapter)
       assert_equal "'1','2','3'", bind(":a", a: SimpleEnumerable.new([1, 2, 3]))
     else
       assert_equal "1,2,3", bind(":a", a: SimpleEnumerable.new([1, 2, 3]))
@@ -188,7 +188,7 @@ def test_bind_empty_enumerable
 
   def test_bind_range
     quoted_abc = %(#{ActiveRecord::Base.connection.quote('a')},#{ActiveRecord::Base.connection.quote('b')},#{ActiveRecord::Base.connection.quote('c')})
-    if current_adapter?(:Mysql2Adapter)
+    if current_adapter?(:Mysql2Adapter, :TrilogyAdapter)
       assert_equal "'0'", bind("?", 0..0)
       assert_equal "'1','2','3'", bind("?", 1..3)
     else
diff --git a/activerecord/test/cases/schema_dumper_test.rb b/activerecord/test/cases/schema_dumper_test.rb
index 945ed2401fee5..5998ecbb258af 100644
--- a/activerecord/test/cases/schema_dumper_test.rb
+++ b/activerecord/test/cases/schema_dumper_test.rb
@@ -125,7 +125,7 @@ def test_schema_dump_includes_limit_constraint_for_integer_columns
       # int 3 is 4 bytes in postgresql
       assert_match %r{"c_int_3"(?!.*limit)}, output
       assert_match %r{"c_int_4"(?!.*limit)}, output
-    elsif current_adapter?(:Mysql2Adapter)
+    elsif current_adapter?(:Mysql2Adapter, :TrilogyAdapter)
       assert_match %r{c_int_1.*limit: 1}, output
       assert_match %r{c_int_2.*limit: 2}, output
       assert_match %r{c_int_3.*limit: 3}, output
@@ -169,7 +169,7 @@ def test_schema_dump_with_regexp_ignored_table
 
   def test_schema_dumps_index_columns_in_right_order
     index_definition = dump_table_schema("companies").split(/\n/).grep(/t\.index.*company_index/).first.strip
-    if current_adapter?(:Mysql2Adapter)
+    if current_adapter?(:Mysql2Adapter, :TrilogyAdapter)
       if ActiveRecord::Base.connection.supports_index_sort_order?
         assert_equal 't.index ["firm_id", "type", "rating"], name: "company_index", length: { type: 10 }, order: { rating: :desc }', index_definition
       else
@@ -202,7 +202,7 @@ def test_schema_dumps_index_sort_order
 
   def test_schema_dumps_index_length
     index_definition = dump_table_schema("companies").split(/\n/).grep(/t\.index.*_name_and_description/).first.strip
-    if current_adapter?(:Mysql2Adapter)
+    if current_adapter?(:Mysql2Adapter, :TrilogyAdapter)
       assert_equal 't.index ["name", "description"], name: "index_companies_on_name_and_description", length: 10', index_definition
     else
       assert_equal 't.index ["name", "description"], name: "index_companies_on_name_and_description"', index_definition
@@ -212,7 +212,7 @@ def test_schema_dumps_index_length
   if ActiveRecord::Base.connection.supports_check_constraints?
     def test_schema_dumps_check_constraints
       constraint_definition = dump_table_schema("products").split(/\n/).grep(/t.check_constraint.*products_price_check/).first.strip
-      if current_adapter?(:Mysql2Adapter)
+      if current_adapter?(:Mysql2Adapter, :TrilogyAdapter)
         assert_equal 't.check_constraint "`price` > `discounted_price`", name: "products_price_check"', constraint_definition
       else
         assert_equal 't.check_constraint "price > discounted_price", name: "products_price_check"', constraint_definition
@@ -291,7 +291,7 @@ def test_schema_dump_expression_indices
 
       if current_adapter?(:PostgreSQLAdapter)
         assert_match %r{CASE.+lower\(\(name\)::text\).+END\) DESC"\z}i, index_definition
-      elsif current_adapter?(:Mysql2Adapter)
+      elsif current_adapter?(:Mysql2Adapter, :TrilogyAdapter)
         assert_match %r{CASE.+lower\(`name`\).+END\) DESC"\z}i, index_definition
       elsif current_adapter?(:SQLite3Adapter)
         assert_match %r{CASE.+lower\(name\).+END\) DESC"\z}i, index_definition
@@ -301,7 +301,7 @@ def test_schema_dump_expression_indices
     end
   end
 
-  if current_adapter?(:Mysql2Adapter)
+  if current_adapter?(:Mysql2Adapter, :TrilogyAdapter)
     def test_schema_dump_includes_length_for_mysql_binary_fields
       output = dump_table_schema "binary_fields"
       assert_match %r{t\.binary\s+"var_binary",\s+limit: 255$}, output
diff --git a/activerecord/test/cases/serialized_attribute_test.rb b/activerecord/test/cases/serialized_attribute_test.rb
index c2869f806ee5e..8ef49bd47ee6d 100644
--- a/activerecord/test/cases/serialized_attribute_test.rb
+++ b/activerecord/test/cases/serialized_attribute_test.rb
@@ -358,7 +358,7 @@ def test_newly_emptied_serialized_hash_is_changed
     assert_equal({}, topic.content)
   end
 
-  if current_adapter?(:Mysql2Adapter)
+  if current_adapter?(:Mysql2Adapter, :TrilogyAdapter)
     def test_is_not_changed_when_stored_in_mysql_blob
       value = %w(Fée)
       model = BinaryField.create!(normal_blob: value, normal_text: value)
diff --git a/activerecord/test/cases/tasks/database_tasks_test.rb b/activerecord/test/cases/tasks/database_tasks_test.rb
index 0f4b94c01fc20..ab095fd9b2d2a 100644
--- a/activerecord/test/cases/tasks/database_tasks_test.rb
+++ b/activerecord/test/cases/tasks/database_tasks_test.rb
@@ -52,6 +52,7 @@ def assert_called_for_configs(method_name, configs, &block)
 
   ADAPTERS_TASKS = {
     mysql2:     :mysql_tasks,
+    trilogy:    :mysql_tasks,
     postgresql: :postgresql_tasks,
     sqlite3:    :sqlite_tasks
   }
diff --git a/activerecord/test/cases/test_case.rb b/activerecord/test/cases/test_case.rb
index d75bccd2cdcd8..518e13aeac6c8 100644
--- a/activerecord/test/cases/test_case.rb
+++ b/activerecord/test/cases/test_case.rb
@@ -255,7 +255,7 @@ def self.run(*args)
 
   class AbstractMysqlTestCase < TestCase
     def self.run(*args)
-      super if current_adapter?(:Mysql2Adapter)
+      super if current_adapter?(:Mysql2Adapter) || current_adapter?(:TrilogyAdapter)
     end
   end
 
@@ -265,6 +265,13 @@ def self.run(*args)
     end
   end
 
+  class TrilogyTestCase < TestCase
+    def self.run(*args)
+      super if current_adapter?(:TrilogyAdapter)
+    end
+  end
+
+
   class SQLite3TestCase < TestCase
     def self.run(*args)
       super if current_adapter?(:SQLite3Adapter)
diff --git a/activerecord/test/cases/time_precision_test.rb b/activerecord/test/cases/time_precision_test.rb
index e3c4e1e78558b..8e7298dd336d4 100644
--- a/activerecord/test/cases/time_precision_test.rb
+++ b/activerecord/test/cases/time_precision_test.rb
@@ -45,7 +45,7 @@ def test_time_precision_is_truncated_on_assignment
       assert_equal 123456000, foo.finish.nsec
     end
 
-    unless current_adapter?(:Mysql2Adapter)
+    unless current_adapter?(:Mysql2Adapter, :TrilogyAdapter)
       def test_no_time_precision_isnt_truncated_on_assignment
         @connection.create_table(:foos, force: true)
         @connection.add_column :foos, :start,  :time
diff --git a/activerecord/test/cases/unsafe_raw_sql_test.rb b/activerecord/test/cases/unsafe_raw_sql_test.rb
index 46e3c640db0ee..8367fb9ba96ac 100644
--- a/activerecord/test/cases/unsafe_raw_sql_test.rb
+++ b/activerecord/test/cases/unsafe_raw_sql_test.rb
@@ -170,6 +170,7 @@ class UnsafeRawSqlTest < ActiveRecord::TestCase
     collation_name = {
       "PostgreSQL" => "C",
       "Mysql2" => "utf8mb4_bin",
+      "Trilogy" => "utf8mb4_bin",
       "SQLite" => "binary"
     }[ActiveRecord::Base.connection.adapter_name]
 
diff --git a/activerecord/test/cases/validations/uniqueness_validation_test.rb b/activerecord/test/cases/validations/uniqueness_validation_test.rb
index 88d1909f70c17..118c66320004b 100644
--- a/activerecord/test/cases/validations/uniqueness_validation_test.rb
+++ b/activerecord/test/cases/validations/uniqueness_validation_test.rb
@@ -359,7 +359,7 @@ def test_validate_uniqueness_by_default_database_collation
     assert_not topic1.valid?
     assert_not topic1.save
 
-    if current_adapter?(:Mysql2Adapter)
+    if current_adapter?(:Mysql2Adapter, :TrilogyAdapter)
       # Case insensitive collation (utf8mb4_0900_ai_ci) by default.
       # Should not allow "David" if "david" exists.
       assert_not topic2.valid?
@@ -440,7 +440,7 @@ def test_validate_uniqueness_with_limit
 
       e2 = Event.create(title: "abcdefgh")
       assert_not e2.valid?, "Created an event whose title is not unique"
-    elsif current_adapter?(:Mysql2Adapter, :PostgreSQLAdapter, :OracleAdapter, :SQLServerAdapter)
+    elsif current_adapter?(:Mysql2Adapter, :TrilogyAdapter, :PostgreSQLAdapter, :OracleAdapter, :SQLServerAdapter)
       assert_raise(ActiveRecord::ValueTooLong) do
         Event.create(title: "abcdefgh")
       end
@@ -459,7 +459,7 @@ def test_validate_uniqueness_with_limit_and_utf8
 
       e2 = Event.create(title: "一二三四五六七八")
       assert_not e2.valid?, "Created an event whose title is not unique"
-    elsif current_adapter?(:Mysql2Adapter, :PostgreSQLAdapter, :OracleAdapter, :SQLServerAdapter)
+    elsif current_adapter?(:Mysql2Adapter, :TrilogyAdapter, :PostgreSQLAdapter, :OracleAdapter, :SQLServerAdapter)
       assert_raise(ActiveRecord::ValueTooLong) do
         Event.create(title: "一二三四五六七八")
       end
diff --git a/activerecord/test/cases/view_test.rb b/activerecord/test/cases/view_test.rb
index 4a1afd1199c72..33a6980521f52 100644
--- a/activerecord/test/cases/view_test.rb
+++ b/activerecord/test/cases/view_test.rb
@@ -158,7 +158,7 @@ def test_does_not_dump_view_as_table
 
   class UpdateableViewTest < ActiveRecord::TestCase
     # SQLite does not support CREATE, INSERT, and DELETE for VIEW
-    if current_adapter?(:Mysql2Adapter, :SQLServerAdapter, :PostgreSQLAdapter)
+    if current_adapter?(:Mysql2Adapter, :TrilogyAdapter, :SQLServerAdapter, :PostgreSQLAdapter)
       self.use_transactional_tests = false
       fixtures :books
 
@@ -202,7 +202,7 @@ def test_update_record_to_fail_view_conditions
           book.reload
         end
       end
-    end # end of `if current_adapter?(:Mysql2Adapter, :PostgreSQLAdapter, :SQLServerAdapter)`
+    end # end of `if current_adapter?(:Mysql2Adapter, :TrilogyAdapter, :PostgreSQLAdapter, :SQLServerAdapter)`
   end
 end # end of `if ActiveRecord::Base.connection.supports_views?`
 
diff --git a/activerecord/test/config.example.yml b/activerecord/test/config.example.yml
index 09aeb917f8b00..f290a0b2eedc9 100644
--- a/activerecord/test/config.example.yml
+++ b/activerecord/test/config.example.yml
@@ -1,5 +1,37 @@
 default_connection: <%= defined?(JRUBY_VERSION) ? 'jdbcsqlite3' : 'sqlite3' %>
 
+mysql: &mysql
+  arunit:
+    username: rails
+    encoding: utf8mb4
+    collation: utf8mb4_unicode_ci
+  <% if ENV['MYSQL_PREPARED_STATEMENTS'] %>
+    prepared_statements: true
+  <% else %>
+    prepared_statements: false
+  <% end %>
+  <% if ENV['MYSQL_HOST'] %>
+    host: <%= ENV['MYSQL_HOST'] %>
+  <% end %>
+  <% if ENV['MYSQL_SOCK'] %>
+    socket: "<%= ENV['MYSQL_SOCK'] %>"
+  <% end %>
+  arunit2:
+    username: rails
+    encoding: utf8mb4
+    collation: utf8mb4_general_ci
+  <% if ENV['MYSQL_PREPARED_STATEMENTS'] %>
+    prepared_statements: true
+  <% else %>
+    prepared_statements: false
+  <% end %>
+  <% if ENV['MYSQL_HOST'] %>
+    host: <%= ENV['MYSQL_HOST'] %>
+  <% end %>
+  <% if ENV['MYSQL_SOCK'] %>
+    socket: "<%= ENV['MYSQL_SOCK'] %>"
+  <% end %>
+
 connections:
   jdbcderby:
     arunit:  activerecord_unittest
@@ -36,36 +68,7 @@ connections:
       timeout:  5000
 
   mysql2:
-    arunit:
-      username: rails
-      encoding: utf8mb4
-      collation: utf8mb4_unicode_ci
-<% if ENV['MYSQL_PREPARED_STATEMENTS'] %>
-      prepared_statements: true
-<% else %>
-      prepared_statements: false
-<% end %>
-<% if ENV['MYSQL_HOST'] %>
-      host: <%= ENV['MYSQL_HOST'] %>
-<% end %>
-<% if ENV['MYSQL_SOCK'] %>
-      socket: "<%= ENV['MYSQL_SOCK'] %>"
-<% end %>
-    arunit2:
-      username: rails
-      encoding: utf8mb4
-      collation: utf8mb4_general_ci
-<% if ENV['MYSQL_PREPARED_STATEMENTS'] %>
-      prepared_statements: true
-<% else %>
-      prepared_statements: false
-<% end %>
-<% if ENV['MYSQL_HOST'] %>
-      host: <%= ENV['MYSQL_HOST'] %>
-<% end %>
-<% if ENV['MYSQL_SOCK'] %>
-      socket: "<%= ENV['MYSQL_SOCK'] %>"
-<% end %>
+    <<: *mysql
 
   oracle:
      arunit:
@@ -107,3 +110,6 @@ connections:
     arunit2:
       adapter: sqlite3
       database: ':memory:'
+
+  trilogy:
+    <<: *mysql
diff --git a/activerecord/test/schema/schema.rb b/activerecord/test/schema/schema.rb
index 7e6ae87e5ad51..0ba4e10fbd400 100644
--- a/activerecord/test/schema/schema.rb
+++ b/activerecord/test/schema/schema.rb
@@ -205,7 +205,7 @@
   create_table :carriers, force: true
 
   create_table :carts, force: true, primary_key: [:shop_id, :id] do |t|
-    if ActiveRecord::TestCase.current_adapter?(:Mysql2Adapter)
+    if ActiveRecord::TestCase.current_adapter?(:Mysql2Adapter, :TrilogyAdapter)
       t.bigint :id, index: true, auto_increment: true, null: false
     else
       t.bigint :id, index: true, null: false
diff --git a/activerecord/test/support/adapter_helper.rb b/activerecord/test/support/adapter_helper.rb
index b09053011fd0d..2396df12b5129 100644
--- a/activerecord/test/support/adapter_helper.rb
+++ b/activerecord/test/support/adapter_helper.rb
@@ -14,20 +14,20 @@ def in_memory_db?
   end
 
   def mysql_enforcing_gtid_consistency?
-    current_adapter?(:Mysql2Adapter) && "ON" == ActiveRecord::Base.connection.show_variable("enforce_gtid_consistency")
+    current_adapter?(:Mysql2Adapter, :TrilogyAdapter) && "ON" == ActiveRecord::Base.connection.show_variable("enforce_gtid_consistency")
   end
 
   def supports_default_expression?
     if current_adapter?(:PostgreSQLAdapter)
       true
-    elsif current_adapter?(:Mysql2Adapter)
+    elsif current_adapter?(:Mysql2Adapter, :TrilogyAdapter)
       conn = ActiveRecord::Base.connection
       !conn.mariadb? && conn.database_version >= "8.0.13"
     end
   end
 
   def supports_non_unique_constraint_name?
-    if current_adapter?(:Mysql2Adapter)
+    if current_adapter?(:Mysql2Adapter, :TrilogyAdapter)
       conn = ActiveRecord::Base.connection
       conn.mariadb?
     else
@@ -36,7 +36,7 @@ def supports_non_unique_constraint_name?
   end
 
   def supports_text_column_with_default?
-    if current_adapter?(:Mysql2Adapter)
+    if current_adapter?(:Mysql2Adapter, :TrilogyAdapter)
       conn = ActiveRecord::Base.connection
       conn.mariadb? && conn.database_version >= "10.2.1"
     else
diff --git a/activerecord/test/support/marshal_compatibility_fixtures/Trilogy/rails_6_1_topic.dump b/activerecord/test/support/marshal_compatibility_fixtures/Trilogy/rails_6_1_topic.dump
new file mode 100644
index 0000000000000..7803d413e73fc
Binary files /dev/null and b/activerecord/test/support/marshal_compatibility_fixtures/Trilogy/rails_6_1_topic.dump differ
diff --git a/activerecord/test/support/marshal_compatibility_fixtures/Trilogy/rails_6_1_topic_associations.dump b/activerecord/test/support/marshal_compatibility_fixtures/Trilogy/rails_6_1_topic_associations.dump
new file mode 100644
index 0000000000000..e9f49fd9a310d
Binary files /dev/null and b/activerecord/test/support/marshal_compatibility_fixtures/Trilogy/rails_6_1_topic_associations.dump differ
diff --git a/activerecord/test/support/marshal_compatibility_fixtures/Trilogy/rails_7_1_topic.dump b/activerecord/test/support/marshal_compatibility_fixtures/Trilogy/rails_7_1_topic.dump
new file mode 100644
index 0000000000000..7eae10a1b9f9f
Binary files /dev/null and b/activerecord/test/support/marshal_compatibility_fixtures/Trilogy/rails_7_1_topic.dump differ
diff --git a/activerecord/test/support/marshal_compatibility_fixtures/Trilogy/rails_7_1_topic_associations.dump b/activerecord/test/support/marshal_compatibility_fixtures/Trilogy/rails_7_1_topic_associations.dump
new file mode 100644
index 0000000000000..c483498306ba6
Binary files /dev/null and b/activerecord/test/support/marshal_compatibility_fixtures/Trilogy/rails_7_1_topic_associations.dump differ
diff --git a/railties/lib/rails/generators/database.rb b/railties/lib/rails/generators/database.rb
index 2dbdd7d09384c..c1f80591aabea 100644
--- a/railties/lib/rails/generators/database.rb
+++ b/railties/lib/rails/generators/database.rb
@@ -4,7 +4,7 @@ module Rails
   module Generators
     module Database # :nodoc:
       JDBC_DATABASES = %w( jdbcmysql jdbcsqlite3 jdbcpostgresql jdbc )
-      DATABASES = %w( mysql postgresql sqlite3 oracle sqlserver ) + JDBC_DATABASES
+      DATABASES = %w( mysql trilogy postgresql sqlite3 oracle sqlserver ) + JDBC_DATABASES
 
       def initialize(*)
         super
@@ -14,6 +14,7 @@ def initialize(*)
       def gem_for_database(database = options[:database])
         case database
         when "mysql"          then ["mysql2", ["~> 0.5"]]
+        when "trilogy"        then ["trilogy", ["~> 2.4"]]
         when "postgresql"     then ["pg", ["~> 1.1"]]
         when "sqlite3"        then ["sqlite3", ["~> 1.4"]]
         when "oracle"         then ["activerecord-oracle_enhanced-adapter", nil]
diff --git a/railties/lib/rails/generators/rails/app/templates/config/databases/trilogy.yml.tt b/railties/lib/rails/generators/rails/app/templates/config/databases/trilogy.yml.tt
new file mode 100644
index 0000000000000..a22ccca2acbfe
--- /dev/null
+++ b/railties/lib/rails/generators/rails/app/templates/config/databases/trilogy.yml.tt
@@ -0,0 +1,59 @@
+# MySQL. Versions 5.5.8 and up are supported.
+#
+# Install the MySQL driver
+#   gem install trilogy
+#
+# Ensure the MySQL gem is defined in your Gemfile
+#   gem "trilogy"
+#
+# And be sure to use new-style password hashing:
+#   https://dev.mysql.com/doc/refman/5.7/en/password-hashing.html
+#
+default: &default
+  adapter: trilogy
+  encoding: utf8mb4
+  pool: <%%= ENV.fetch("RAILS_MAX_THREADS") { 5 } %>
+  username: root
+  password:
+<% if mysql_socket -%>
+  socket: <%= mysql_socket %>
+<% else -%>
+  host: localhost
+<% end -%>
+
+development:
+  <<: *default
+  database: <%= app_name %>_development
+
+# Warning: The database defined as "test" will be erased and
+# re-generated from your development database when you run "rake".
+# Do not set this db to the same as development or production.
+test:
+  <<: *default
+  database: <%= app_name %>_test
+
+# As with config/credentials.yml, you never want to store sensitive information,
+# like your database password, in your source code. If your source code is
+# ever seen by anyone, they now have access to your database.
+#
+# Instead, provide the password or a full connection URL as an environment
+# variable when you boot the app. For example:
+#
+#   DATABASE_URL="trilogy://myuser:mypass@localhost/somedatabase"
+#
+# If the connection URL is provided in the special DATABASE_URL environment
+# variable, Rails will automatically merge its configuration values on top of
+# the values provided in this file. Alternatively, you can specify a connection
+# URL environment variable explicitly:
+#
+#   production:
+#     url: <%%= ENV["MY_APP_DATABASE_URL"] %>
+#
+# Read https://guides.rubyonrails.org/configuring.html#configuring-a-database
+# for a full overview on how database connection configuration can be specified.
+#
+production:
+  <<: *default
+  database: <%= app_name %>_production
+  username: <%= app_name %>
+  password: <%%= ENV["<%= app_name.upcase %>_DATABASE_PASSWORD"] %>
diff --git a/railties/test/commands/db_system_change_test.rb b/railties/test/commands/db_system_change_test.rb
index 273203653b2c0..55caddb85b23c 100644
--- a/railties/test/commands/db_system_change_test.rb
+++ b/railties/test/commands/db_system_change_test.rb
@@ -25,9 +25,9 @@ class Rails::Command::DbSystemChangeTest < ActiveSupport::TestCase
     assert_match <<~MSG.squish, output
       Invalid value for --to option.
       Supported preconfigurations are:
-      mysql, postgresql, sqlite3, oracle,
-      sqlserver, jdbcmysql, jdbcsqlite3,
-      jdbcpostgresql, jdbc.
+      mysql, trilogy, postgresql, sqlite3,
+      oracle, sqlserver, jdbcmysql,
+      jdbcsqlite3, jdbcpostgresql, jdbc.
     MSG
   end
 
diff --git a/railties/test/generators/db_system_change_generator_test.rb b/railties/test/generators/db_system_change_generator_test.rb
index e19de3081a844..f664c79e707cb 100644
--- a/railties/test/generators/db_system_change_generator_test.rb
+++ b/railties/test/generators/db_system_change_generator_test.rb
@@ -25,9 +25,9 @@ class ChangeGeneratorTest < Rails::Generators::TestCase
             assert_match <<~MSG.squish, output
               Invalid value for --to option.
               Supported preconfigurations are:
-              mysql, postgresql, sqlite3, oracle,
-              sqlserver, jdbcmysql, jdbcsqlite3,
-              jdbcpostgresql, jdbc.
+              mysql, trilogy, postgresql, sqlite3,
+              oracle, sqlserver, jdbcmysql,
+              jdbcsqlite3, jdbcpostgresql, jdbc.
             MSG
           end