据我了解,与
我需要对以前的研究进行研究
你的意思是你想做嵌套查询: aselect
嵌套在 a 中select
。这是可能的py-sql
:你select
第一次在你的桌子上打电话。假设您将其命名为select
: subselect
。现在,您调用select
从subselect
第一个查询表中选择行。这是来自py-sql
doc的示例。
>>> user_group = Table('user_group')
>>> subselect = user_group.select(user_group.user,
... where=(user_group.active == True))
>>> user = Table('user')
>>> tuple(user.select(user.id, where=(user.id.in_(subselect))))
('SELECT "a"."id" FROM "user" AS "a" WHERE ("a"."id" IN (SELECT "b"."user"
FROM "user_group" AS "b"
WHERE ("b"."active" = %s)))', (True,))
>>> tuple(subselect.select(subselect.user))
('SELECT "a"."user" FROM (SELECT "b"."user"
FROM "user_group" AS "b"
WHERE ("b"."active" = %s)) AS "a"', (True,))