Question

我有2张桌子


Table 1

ID  Status
1   D
2   F
3   D


Table 2

SID ID  Approve
1   1   N
2   1   Y
3   1   Y
4   2   Y
5   3   Y

Result:-  Should be 
Table 1 (ID, Status)
3, D
2,F

不应显示1（其中一个子行在批准列中有N）

我需要一个查询来连接ID上的2个表，并查找其Approve列中没有N的记录。有没有人知道如何实现这个？

我试过

SELECT * FROM Table1 AS t1 
INNER JOIN Table2 AS t2 
ON t2.id = t1.id 
WHERE t2.Approve != 'N'

不起作用

Answer 1

SELECT *
FROM Table1 t1
WHERE NOT EXISTS(SELECT * FROM Table2 t2 WHERE t2.ID = t1.ID AND t2.Approve = 'N')

Answer 2

更高效，更容易阅读如下：

SELECT * FROM Table1 AS t1 
LEFT JOIN Table2 AS t2 
ON t2.id = t1.id 
group by t1.id HAVING sum(t2.approve='Y') = count(t1.id)

Answer 3

请尝试

SELECT distinct t1.* 
FROM Table1 AS t1 
INNER JOIN Table2 AS tyes
ON tyes.id = t1.id
AND tyes.approve ='Y'
LEFT OUTER JOIN Table2 as tno
ON tno.id = t1.id
AND tno.approve ='N'
where tno.sid is null

它将选择任何明确批准且永不拒绝的行

Answer 4

Select * from table1 where id not in (select id from table2 where approve = 'N')

Answer 5

仍然返回ID 1，因为表2中还有一条记录，其中对于ID 1，approve ='Y'。如果要排除任何SID批准为“N”的ID，则必须使用子查询;大致是：

SELECT t1.ID,T1.Status FROM Table1 AS t1 INNER JOIN Table2 AS t2 ON t2.id = t1.id
where t1.id NOT IN (select id from Table2 where approve = 'N' and id = t1.id)

的问候，
斯泰恩

需要帮助加入问题

5 个答案: