1 files changed, 69 insertions, 0 deletions
diff --git a/activerecord/lib/active_record/connection_adapters/mysql/schema_statements.rb b/activerecord/lib/active_record/connection_adapters/mysql/schema_statements.rb
new file mode 100644
index 0000000000..9e2d0fb5e7
--- /dev/null
+++ b/activerecord/lib/active_record/connection_adapters/mysql/schema_statements.rb
@@ -0,0 +1,69 @@
+module ActiveRecord
+  module ConnectionAdapters
+    module MySQL
+      module SchemaStatements # :nodoc:
+        private
+          def schema_creation
+            MySQL::SchemaCreation.new(self)
+          end
+
+          def create_table_definition(*args)
+            MySQL::TableDefinition.new(*args)
+          end
+
+          def new_column_from_field(table_name, field)
+            type_metadata = fetch_type_metadata(field[:Type], field[:Extra])
+            if type_metadata.type == :datetime && field[:Default] == "CURRENT_TIMESTAMP"
+              default, default_function = nil, field[:Default]
+            else
+              default, default_function = field[:Default], nil
+            end
+
+            MySQL::Column.new(
+              field[:Field],
+              default,
+              type_metadata,
+              field[:Null] == "YES",
+              table_name,
+              default_function,
+              field[:Collation],
+              comment: field[:Comment].presence
+            )
+          end
+
+          def fetch_type_metadata(sql_type, extra = "")
+            MySQL::TypeMetadata.new(super(sql_type), extra: extra)
+          end
+
+          def extract_foreign_key_action(specifier)
+            super unless specifier == "RESTRICT"
+          end
+
+          def data_source_sql(name = nil, type: nil)
+            scope = quoted_scope(name, type: type)
+
+            sql = "SELECT table_name FROM information_schema.tables"
+            sql << " WHERE table_schema = #{scope[:schema]}"
+            sql << " AND table_name = #{scope[:name]}" if scope[:name]
+            sql << " AND table_type = #{scope[:type]}" if scope[:type]
+            sql
+          end
+
+          def quoted_scope(name = nil, type: nil)
+            schema, name = extract_schema_qualified_name(name)
+            scope = {}
+            scope[:schema] = schema ? quote(schema) : "database()"
+            scope[:name] = quote(name) if name
+            scope[:type] = quote(type) if type
+            scope
+          end
+
+          def extract_schema_qualified_name(string)
+            schema, name = string.to_s.scan(/[^`.\s]+|`[^`]*`/)
+            schema, name = nil, schema unless name
+            [schema, name]
+          end
+      end
+    end
+  end
+end