用extra(select=None, where=None, params=None, tables=None, order_by=None,select_params=None) 查询数据库时，怎么样写tables这参数使得可以查多个表，并且可以对表进行命别名， 形如： SELECT T1 *, T2 * FROM Table1 T1, Table2 T2;
我用了如下几种方法都不行
tables=[('Table1', 'T1'), ('Table2', 'T2')]
tables=['Table1 T1', 'Table2 T2']
tables=['"Table1" AS "T1"', '"Table2" AS "T2"']
tables=['Table1 AS T1', 'Table2 AS T2']
