base.py 文件源码

def returning_clause(self, stmt, returning_cols):
        columns = []
        binds = []
        for i, column in enumerate(
                expression._select_iterables(returning_cols)):
            if column.type._has_column_expression:
                col_expr = column.type.column_expression(column)
            else:
                col_expr = column
            outparam = sql.outparam("ret_%d" % i, type_=column.type)
            self.binds[outparam.key] = outparam
            binds.append(
                self.bindparam_string(self._truncate_bindparam(outparam)))
            columns.append(
                self.process(col_expr, within_columns_clause=False))

            self._add_to_result_map(
                outparam.key, outparam.key,
                (column, getattr(column, 'name', None),
                 getattr(column, 'key', None)),
                column.type
            )

        return 'RETURNING ' + ', '.join(columns) + " INTO " + ", ".join(binds)