sql-server-2008 - 用于连接 3 个表的 sql 查询

Question

表 A：用户名

表 B: accid userid accno

表c：loanid userid amt

嗨 frnds，我想从表 A 中获取客户的姓名，从表 B 中获取 accno 并且它们不包含在表 c 中。帮我

Answer 1

SELECT a.name, b.accno
FROM a inner join b on b.userid = a.userid
where a.userid not in (select distinct userid from c)

我认为这个查询怎么样？

Answer 2

尝试：

SELECT a.name, b.accno
FROM tableA a 
JOIN tableB b on a.userid = b.userid
LEFT JOIN tableC c on a.userid = c.userid
WHERE c.userid IS NULL

进行左连接并检查返回的值是否为空，检查表 c 中是否没有表 a 和表 b 中的记录。

Answer 3

解决方案1：

;with cte as
(Select a.name,b.accno,a.userid
from tableA a
join tableB b
on a.userid = b.userid)

select x.name,x.accno
from cte x 
where x.userid not in (select userid from tableC)

解决方案2：

;with cte as
(Select a.name,b.accno,a.userid
from tableA a join tableB b 
on a.userid = b.userid)
select x.name,x.accno
from cte x 
where x.userid in(select c.userid 
                 from cte c 
                 except 
                 select tc.userid 
                from tableC tc)

解决方案 3

;with cte as
(Select a.name,b.accno,a.userid
from tableA a join tableB b 
on a.userid = b.userid)

select x.name,x.accno
from cte x
left join tableC tc
on x.userid = tc.userid
where tc.userid is null