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

# File activerecord/lib/active_record/connection_adapters/abstract_mysql_adapter.rb, line 29
      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)

        @statements = StatementPool.new(self.class.type_cast_config_to_integer(config[:statement_limit]))

        if version < "5.1.10"
          raise "Your version of MySQL (#{version_string}) is too old. Active Record supports MySQL >= 5.1.10."
        end
      end

# File activerecord/lib/active_record/connection_adapters/abstract_mysql_adapter.rb, line 199
      def begin_db_transaction
        execute "BEGIN"
      end

# File activerecord/lib/active_record/connection_adapters/abstract_mysql_adapter.rb, line 203
      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 271
      def charset
        show_variable "character_set_database"
      end

# File activerecord/lib/active_record/connection_adapters/abstract_mysql_adapter.rb, line 165
      def clear_cache!
        reload_type_map
        @statements.clear
      end

# File activerecord/lib/active_record/connection_adapters/abstract_mysql_adapter.rb, line 276
      def collation
        show_variable "collation_database"
      end

# File activerecord/lib/active_record/connection_adapters/abstract_mysql_adapter.rb, line 250
      def create_database(name, options = {})
        if options[:collation]
          execute "CREATE DATABASE #{quote_table_name(name)} DEFAULT COLLATE #{quote_table_name(options[:collation])}"
        else
          execute "CREATE DATABASE #{quote_table_name(name)} DEFAULT CHARACTER SET #{quote_table_name(options[:charset] || 'utf8')}"
        end
      end

# File activerecord/lib/active_record/connection_adapters/abstract_mysql_adapter.rb, line 266
      def current_database
        query_value("SELECT database()", "SCHEMA")
      end

# File activerecord/lib/active_record/connection_adapters/abstract_mysql_adapter.rb, line 339
      def drop_table(table_name, options = {})
        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 228
      def empty_insert_statement_value
        "VALUES ()"
      end

# File activerecord/lib/active_record/connection_adapters/abstract_mysql_adapter.rb, line 184
      def execute(sql, name = nil)
        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 174
      def explain(arel, binds = [])
        sql     = "EXPLAIN #{to_sql(arel, binds)}"
        start   = Time.now
        result  = exec_query(sql, "EXPLAIN", binds)
        elapsed = Time.now - start

        MySQL::ExplainPrettyPrinter.new.pp(result, elapsed)
      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.strip_heredoc, "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 131
      def index_algorithms
        { default: "ALGORITHM = DEFAULT".dup, copy: "ALGORITHM = COPY".dup, inplace: "ALGORITHM = INPLACE".dup }
      end

# File activerecord/lib/active_record/connection_adapters/abstract_mysql_adapter.rb, line 529
      def insert_fixtures_set(fixture_set, tables_to_delete = [])
        with_multi_statements do
          super { discard_remaining_results }
        end
      end

# File activerecord/lib/active_record/connection_adapters/abstract_mysql_adapter.rb, line 127
      def native_database_types
        NATIVE_DATABASE_TYPES
      end

# File activerecord/lib/active_record/connection_adapters/abstract_mysql_adapter.rb, line 236
      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 343
      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 319
      def rename_table(table_name, new_name)
        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 472
      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 521
      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 115
      def supports_advisory_locks?
        true
      end

# File activerecord/lib/active_record/connection_adapters/abstract_mysql_adapter.rb, line 99
      def supports_datetime_with_precision?
        if mariadb?
          version >= "5.3.0"
        else
          version >= "5.6.4"
        end
      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 91
      def supports_foreign_keys?
        true
      end

# File activerecord/lib/active_record/connection_adapters/abstract_mysql_adapter.rb, line 75
      def supports_index_sort_order?
        !mariadb? && 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 79
      def supports_transaction_isolation?
        true
      end

# File activerecord/lib/active_record/connection_adapters/abstract_mysql_adapter.rb, line 95
      def supports_views?
        true
      end

# File activerecord/lib/active_record/connection_adapters/abstract_mysql_adapter.rb, line 107
      def supports_virtual_columns?
        if mariadb?
          version >= "5.2.0"
        else
          version >= "5.7.5"
        end
      end

# File activerecord/lib/active_record/connection_adapters/abstract_mysql_adapter.rb, line 280
      def truncate(table_name, name = nil)
        execute "TRUNCATE TABLE #{quote_table_name(table_name)}", name
      end