Question

我该如何使这项工作？我有一个表u_uzivatele，我想在表b_objednavky上加入它，但我也不希望加入表u_uzivatele中的行，这些行可以加入表bw_paid_orders 1}}并且不符合WHERE条款。现在，SELECT语句返回表，其中包含表uzivatele中的行，这些行也在表bw_paid_orders中，并满足WHERE子句的条件。但是我无法在表u_uzivatele上加入它，因为返回了多行。

SELECT STMT

FROM b_objednavky INNER JOIN u_uzivatele ON b_objednavky.uzivatel = 
( 
       SELECT u_uzivatele.id 
       FROM   u_uzivatele 
       JOIN   bw_paid_orders 
       ON     u_uzivatele.id = bw_paid_orders.user_id 
       WHERE  bw_paid_orders.active_thru < now() + interval '6 months' ) uzivatele

Answer 1

您希望仅u_uzivatele加入不存在某个条目的bw_paid_orders条记录。因此，请使用NOT EXISTS或更简单的NOT IN。

select ...
from b_objednavky o
join u_uzivatele u on  u.id = o.uzivatel
                   and u.id not in (select user_id from bw_paid_orders po 
                                    where active_thru < now() + interval '6 months')

在SELECT语句上连接表

1 个答案: