base.py 文件源码

def pre_exec(self):
        if self.isinsert:
            tbl = self.compiled.statement.table
            seq_column = tbl._autoincrement_column
            insert_has_sequence = seq_column is not None

            if insert_has_sequence:
                self._enable_identity_insert = \
                    seq_column.key in self.compiled_parameters[0]
            else:
                self._enable_identity_insert = False

            if self._enable_identity_insert:
                self.cursor.execute(
                    "SET IDENTITY_INSERT %s ON" %
                    self.dialect.identifier_preparer.format_table(tbl))

        if self.isddl:
            # TODO: to enhance this, we can detect "ddl in tran" on the
            # database settings.  this error message should be improved to
            # include a note about that.
            if not self.should_autocommit:
                raise exc.InvalidRequestError(
                    "The Sybase dialect only supports "
                    "DDL in 'autocommit' mode at this time.")

            self.root_connection.engine.logger.info(
                "AUTOCOMMIT (Assuming no Sybase 'ddl in tran')")

            self.set_ddl_autocommit(
                self.root_connection.connection.connection,
                True)