ActiveRecord::ConnectionAdapters::AbstractMysqlAdapter < ActiveRecord::ConnectionAdapters::AbstractAdapter

# File activerecord/lib/active_record/connection_adapters/abstract_mysql_adapter.rb, line 27
      class_attribute :emulate_booleans, default: true

# File activerecord/lib/active_record/connection_adapters/abstract_mysql_adapter.rb, line 53
      def initialize(connection, logger, connection_options, config)
        super(connection, logger, config)
      end

# File activerecord/lib/active_record/connection_adapters/abstract_mysql_adapter.rb, line 218
      def begin_db_transaction
        execute("BEGIN", "TRANSACTION")
      end

# File activerecord/lib/active_record/connection_adapters/abstract_mysql_adapter.rb, line 222
      def begin_isolated_db_transaction(isolation)
        execute "SET TRANSACTION ISOLATION LEVEL #{transaction_isolation_levels.fetch(isolation)}"
        begin_db_transaction
      end

# File activerecord/lib/active_record/connection_adapters/abstract_mysql_adapter.rb, line 282
      def charset
        show_variable "character_set_database"
      end

# File activerecord/lib/active_record/connection_adapters/abstract_mysql_adapter.rb, line 426
      def check_constraints(table_name)
        if supports_check_constraints?
          scope = quoted_scope(table_name)

          chk_info = exec_query(<<~SQL, "SCHEMA")
            SELECT cc.constraint_name AS 'name',
                  cc.check_clause AS 'expression'
            FROM information_schema.check_constraints cc
            JOIN information_schema.table_constraints tc
            USING (constraint_schema, constraint_name)
            WHERE tc.table_schema = #{scope[:schema]}
              AND tc.table_name = #{scope[:name]}
              AND cc.constraint_schema = #{scope[:schema]}
          SQL

          chk_info.map do |row|
            options = {
              name: row["name"]
            }
            expression = row["expression"]
            expression = expression[1..-2] unless mariadb? # remove parentheses added by mysql
            CheckConstraintDefinition.new(table_name, expression, options)
          end
        else
          raise NotImplementedError
        end
      end

# File activerecord/lib/active_record/connection_adapters/abstract_mysql_adapter.rb, line 287
      def collation
        show_variable "collation_database"
      end

# File activerecord/lib/active_record/connection_adapters/abstract_mysql_adapter.rb, line 257
      def create_database(name, options = {})
        if options[:collation]
          execute "CREATE DATABASE #{quote_table_name(name)} DEFAULT COLLATE #{quote_table_name(options[:collation])}"
        elsif options[:charset]
          execute "CREATE DATABASE #{quote_table_name(name)} DEFAULT CHARACTER SET #{quote_table_name(options[:charset])}"
        elsif row_format_dynamic_by_default?
          execute "CREATE DATABASE #{quote_table_name(name)} DEFAULT CHARACTER SET `utf8mb4`"
        else
          raise "Configure a supported :charset and ensure innodb_large_prefix is enabled to support indexes on varchar(255) string columns."
        end
      end

# File activerecord/lib/active_record/connection_adapters/abstract_mysql_adapter.rb, line 277
      def current_database
        query_value("SELECT database()", "SCHEMA")
      end

# File activerecord/lib/active_record/connection_adapters/abstract_mysql_adapter.rb, line 334
      def drop_table(table_name, **options)
        schema_cache.clear_data_source_cache!(table_name.to_s)
        execute "DROP#{' TEMPORARY' if options[:temporary]} TABLE#{' IF EXISTS' if options[:if_exists]} #{quote_table_name(table_name)}#{' CASCADE' if options[:force] == :cascade}"
      end

# File activerecord/lib/active_record/connection_adapters/abstract_mysql_adapter.rb, line 235
      def empty_insert_statement_value(primary_key = nil)
        "VALUES ()"
      end

# File activerecord/lib/active_record/connection_adapters/abstract_mysql_adapter.rb, line 200
      def execute(sql, name = nil)
        materialize_transactions
        mark_transaction_written_if_write(sql)

        log(sql, name) do
          ActiveSupport::Dependencies.interlock.permit_concurrent_loads do
            @connection.query(sql)
          end
        end
      end

# File activerecord/lib/active_record/connection_adapters/abstract_mysql_adapter.rb, line 390
      def foreign_keys(table_name)
        raise ArgumentError unless table_name.present?

        scope = quoted_scope(table_name)

        fk_info = exec_query(<<~SQL, "SCHEMA")
          SELECT fk.referenced_table_name AS 'to_table',
                 fk.referenced_column_name AS 'primary_key',
                 fk.column_name AS 'column',
                 fk.constraint_name AS 'name',
                 rc.update_rule AS 'on_update',
                 rc.delete_rule AS 'on_delete'
          FROM information_schema.referential_constraints rc
          JOIN information_schema.key_column_usage fk
          USING (constraint_schema, constraint_name)
          WHERE fk.referenced_column_name IS NOT NULL
            AND fk.table_schema = #{scope[:schema]}
            AND fk.table_name = #{scope[:name]}
            AND rc.constraint_schema = #{scope[:schema]}
            AND rc.table_name = #{scope[:name]}
        SQL

        fk_info.map do |row|
          options = {
            column: row["column"],
            name: row["name"],
            primary_key: row["primary_key"]
          }

          options[:on_update] = extract_foreign_key_action(row["on_update"])
          options[:on_delete] = extract_foreign_key_action(row["on_delete"])

          ForeignKeyDefinition.new(table_name, row["to_table"], options)
        end
      end

# File activerecord/lib/active_record/connection_adapters/abstract_mysql_adapter.rb, line 152
      def index_algorithms
        {
          default: "ALGORITHM = DEFAULT",
          copy:    "ALGORITHM = COPY",
          inplace: "ALGORITHM = INPLACE",
          instant: "ALGORITHM = INSTANT",
        }
      end

# File activerecord/lib/active_record/connection_adapters/abstract_mysql_adapter.rb, line 148
      def native_database_types
        NATIVE_DATABASE_TYPES
      end

# File activerecord/lib/active_record/connection_adapters/abstract_mysql_adapter.rb, line 243
      def recreate_database(name, options = {})
        drop_database(name)
        sql = create_database(name, options)
        reconnect!
        sql
      end

# File activerecord/lib/active_record/connection_adapters/abstract_mysql_adapter.rb, line 339
      def rename_index(table_name, old_name, new_name)
        if supports_rename_index?
          validate_index_length!(table_name, new_name)

          execute "ALTER TABLE #{quote_table_name(table_name)} RENAME INDEX #{quote_table_name(old_name)} TO #{quote_table_name(new_name)}"
        else
          super
        end
      end

# File activerecord/lib/active_record/connection_adapters/abstract_mysql_adapter.rb, line 312
      def rename_table(table_name, new_name)
        schema_cache.clear_data_source_cache!(table_name.to_s)
        schema_cache.clear_data_source_cache!(new_name.to_s)
        execute "RENAME TABLE #{quote_table_name(table_name)} TO #{quote_table_name(new_name)}"
        rename_table_indexes(table_name, new_name)
      end

# File activerecord/lib/active_record/connection_adapters/abstract_mysql_adapter.rb, line 484
      def show_variable(name)
        query_value("SELECT @@#{name}", "SCHEMA")
      rescue ActiveRecord::StatementInvalid
        nil
      end

# File activerecord/lib/active_record/connection_adapters/abstract_mysql_adapter.rb, line 535
      def strict_mode?
        self.class.type_cast_config_to_boolean(@config.fetch(:strict, true))
      end

# File activerecord/lib/active_record/connection_adapters/abstract_mysql_adapter.rb, line 128
      def supports_advisory_locks?
        true
      end

# File activerecord/lib/active_record/connection_adapters/abstract_mysql_adapter.rb, line 67
      def supports_bulk_alter?
        true
      end

# File activerecord/lib/active_record/connection_adapters/abstract_mysql_adapter.rb, line 95
      def supports_check_constraints?
        if mariadb?
          database_version >= "10.2.1"
        else
          database_version >= "8.0.16"
        end
      end

# File activerecord/lib/active_record/connection_adapters/abstract_mysql_adapter.rb, line 120
      def supports_common_table_expressions?
        if mariadb?
          database_version >= "10.2.1"
        else
          database_version >= "8.0.1"
        end
      end

# File activerecord/lib/active_record/connection_adapters/abstract_mysql_adapter.rb, line 107
      def supports_datetime_with_precision?
        mariadb? || database_version >= "5.6.4"
      end

# File activerecord/lib/active_record/connection_adapters/abstract_mysql_adapter.rb, line 83
      def supports_explain?
        true
      end

# File activerecord/lib/active_record/connection_adapters/abstract_mysql_adapter.rb, line 75
      def supports_expression_index?
        !mariadb? && database_version >= "8.0.13"
      end

# File activerecord/lib/active_record/connection_adapters/abstract_mysql_adapter.rb, line 91
      def supports_foreign_keys?
        true
      end

# File activerecord/lib/active_record/connection_adapters/abstract_mysql_adapter.rb, line 71
      def supports_index_sort_order?
        !mariadb? && database_version >= "8.0.1"
      end

# File activerecord/lib/active_record/connection_adapters/abstract_mysql_adapter.rb, line 87
      def supports_indexes_in_create?
        true
      end

# File activerecord/lib/active_record/connection_adapters/abstract_mysql_adapter.rb, line 132
      def supports_insert_on_duplicate_skip?
        true
      end

# File activerecord/lib/active_record/connection_adapters/abstract_mysql_adapter.rb, line 136
      def supports_insert_on_duplicate_update?
        true
      end

# File activerecord/lib/active_record/connection_adapters/abstract_mysql_adapter.rb, line 116
      def supports_optimizer_hints?
        !mariadb? && database_version >= "5.7.7"
      end

# File activerecord/lib/active_record/connection_adapters/abstract_mysql_adapter.rb, line 79
      def supports_transaction_isolation?
        true
      end

# File activerecord/lib/active_record/connection_adapters/abstract_mysql_adapter.rb, line 103
      def supports_views?
        true
      end

# File activerecord/lib/active_record/connection_adapters/abstract_mysql_adapter.rb, line 111
      def supports_virtual_columns?
        mariadb? || database_version >= "5.7.5"
      end