[Rails51] Find #primary_keys propertly.

* Support proper ordinal order.
* Bake in schema and full DB identifer support like #column_definitions.

Author: metaskills

lib/active_record/connection_adapters/sqlserver/schema_statements.rb

@@ -85,10 +85,34 @@ def new_column(name, default, sql_type_metadata, null, table_name, default_funct
         end
 
         def primary_keys(table_name)
-          primaries = schema_cache.columns(table_name).select(&:is_primary?).map(&:name)
+          primaries = primary_keys_select(table_name)
           primaries.present? ? primaries : identity_columns(table_name).map(&:name)
         end
 
+        def primary_keys_select(table_name)
+          identifier = database_prefix_identifier(table_name)
+          database = identifier.fully_qualified_database_quoted
+          sql = %{
+            SELECT KCU.COLUMN_NAME AS [name]
+            FROM #{database}.INFORMATION_SCHEMA.KEY_COLUMN_USAGE AS KCU
+            LEFT OUTER JOIN #{database}.INFORMATION_SCHEMA.TABLE_CONSTRAINTS AS TC
+              ON KCU.CONSTRAINT_NAME = TC.CONSTRAINT_NAME
+              AND KCU.CONSTRAINT_NAME = TC.CONSTRAINT_NAME
+              AND KCU.CONSTRAINT_CATALOG = TC.CONSTRAINT_CATALOG
+              AND KCU.CONSTRAINT_SCHEMA = TC.CONSTRAINT_SCHEMA
+              AND TC.CONSTRAINT_TYPE = N'PRIMARY KEY'
+            WHERE KCU.TABLE_NAME = #{prepared_statements ? '@0' : quote(identifier.object)}
+            AND KCU.TABLE_SCHEMA = #{identifier.schema.blank? ? 'schema_name()' : (prepared_statements ? '@1' : quote(identifier.schema))}
+            AND TC.CONSTRAINT_TYPE = N'PRIMARY KEY'
+            ORDER BY KCU.ORDINAL_POSITION ASC
+          }.gsub(/[[:space:]]/, ' ')
+          binds = []
+          nv128 = SQLServer::Type::UnicodeVarchar.new limit: 128
+          binds << Relation::QueryAttribute.new('TABLE_NAME', identifier.object, nv128)
+          binds << Relation::QueryAttribute.new('TABLE_SCHEMA', identifier.schema, nv128) unless identifier.schema.blank?
+          sp_executesql(sql, 'SCHEMA', binds).map { |r| r['name'] }
+        end
+
         def rename_table(table_name, new_name)
           do_execute "EXEC sp_rename '#{table_name}', '#{new_name}'"
           rename_table_indexes(table_name, new_name)
@@ -290,11 +314,7 @@ def initialize_native_database_types
         end
 
         def column_definitions(table_name)
-          identifier = if database_prefix_remote_server?
-            SQLServer::Utils.extract_identifiers("#{database_prefix}#{table_name}")
-          else
-            SQLServer::Utils.extract_identifiers(table_name)
-          end
+          identifier  = database_prefix_identifier(table_name)
           database    = identifier.fully_qualified_database_quoted
           view_exists = view_exists?(table_name)
           view_tblnm  = view_table_name(table_name) if view_exists

lib/active_record/connection_adapters/sqlserver_adapter.rb

@@ -226,6 +226,14 @@ def database_prefix
         @connection_options[:database_prefix]
       end
 
+      def database_prefix_identifier(name)
+        if database_prefix_remote_server?
+          SQLServer::Utils.extract_identifiers("#{database_prefix}#{name}")
+        else
+          SQLServer::Utils.extract_identifiers(name)
+        end
+      end
+
       def version
         self.class::VERSION
       end

test/support/sql_counter_sqlserver.rb

@@ -13,7 +13,7 @@ def capture_sql_ss
     end
 
     ignored_sql = [
-      /INFORMATION_SCHEMA\.(TABLES|VIEWS|COLUMNS)/im,
+      /INFORMATION_SCHEMA\.(TABLES|VIEWS|COLUMNS|KEY_COLUMN_USAGE)/im,
       /SELECT @@version/,
       /SELECT @@TRANCOUNT/,
       /(BEGIN|COMMIT|ROLLBACK|SAVE) TRANSACTION/,