Set precision 6 by default for timestamps (#1057)

Author: aidanharan

CHANGELOG.md

@@ -6,6 +6,10 @@
 - [#1053](https://github.com/rails-sqlserver/activerecord-sqlserver-adapter/pull/1053) Fix insertion of records to non-default schema table using raw SQL
 - [#1059](https://github.com/rails-sqlserver/activerecord-sqlserver-adapter/pull/1059) Fix enums defined on string columns
 
+#### Changed
+
+- [#1057](https://github.com/rails-sqlserver/activerecord-sqlserver-adapter/pull/1057) Set precision 6 by default for timestamps.
+
 ## v7.0.2.0
 
 [Full changelog](https://github.com/rails-sqlserver/activerecord-sqlserver-adapter/compare/v7.0.1.0...v7.0.2.0)

lib/active_record/connection_adapters/sqlserver/schema_statements.rb

@@ -346,7 +346,7 @@ def initialize_native_database_types
             datetime2: { name: "datetime2" },
             datetimeoffset: { name: "datetimeoffset" },
             smalldatetime: { name: "smalldatetime" },
-            timestamp: { name: "datetime" },
+            timestamp: { name: "datetime2(6)" },
             time: { name: "time" },
             char: { name: "char" },
             varchar: { name: "varchar", limit: 8000 },

lib/active_record/connection_adapters/sqlserver/table_definition.rb

@@ -101,11 +101,16 @@ class TableDefinition < ActiveRecord::ConnectionAdapters::TableDefinition
 
         def new_column_definition(name, type, **options)
           case type
-          when :datetime
-            type = :datetime2 if options[:precision]
+          when :datetime, :timestamp
+            # If no precision then default it to 6.
+            options[:precision] = 6 unless options.key?(:precision)
+
+            # If there is precision then column must be of type 'datetime2'.
+            type = :datetime2 unless options[:precision].nil?
           when :primary_key
             options[:is_identity] = true
           end
+
           super
         end
       end

test/cases/coerced_tests.rb

@@ -543,7 +543,7 @@ def test_create_table_with_defaults_coerce
         assert_equal "hello", five.default
       end
 
-      # Rails adds precision 6 by default, sql server uses datetime2 for datetimes with precision
+      # Use precision 6 by default for datetime/timestamp columns. SQL Server uses `datetime2` for date-times with precision.
       coerce_tests! :test_add_column_with_postgresql_datetime_type
       def test_add_column_with_postgresql_datetime_type_coerced
         connection.create_table :testings do |t|
@@ -556,7 +556,7 @@ def test_add_column_with_postgresql_datetime_type_coerced
         assert_equal "datetime2(6)", column.sql_type
       end
 
-      # timestamp is datetime with default limit
+      # Use precision 6 by default for datetime/timestamp columns. SQL Server uses `datetime2` for date-times with precision.
       coerce_tests! :test_change_column_with_timestamp_type
       def test_change_column_with_timestamp_type_coerced
         connection.create_table :testings do |t|
@@ -568,7 +568,20 @@ def test_change_column_with_timestamp_type_coerced
         column = connection.columns(:testings).find { |c| c.name == "foo" }
 
         assert_equal :datetime, column.type
-        assert_equal "datetime", column.sql_type
+        assert_equal "datetime2(6)", column.sql_type
+      end
+
+      # Use precision 6 by default for datetime/timestamp columns. SQL Server uses `datetime2` for date-times with precision.
+      coerce_tests! :test_add_column_with_timestamp_type
+      def test_add_column_with_timestamp_type_coerced
+        connection.create_table :testings do |t|
+          t.column :foo, :timestamp
+        end
+
+        column = connection.columns(:testings).find { |c| c.name == "foo" }
+
+        assert_equal :datetime, column.type
+        assert_equal "datetime2(6)", column.sql_type
       end
     end
   end