Question

如果“WRONG”列永远不会显示“YES”，我想从表中选择一行（多次出现）。这意味着该行存在100次而只有一次 WRONG = yes，然后不在结果中显示任何行。

*如果可能的话，没有变量和while循环请。如果无法完成，请继续并使用变量发布解决方案。

以下是表结构的示例：

表1

USER--WRONG--otherColumns
bob              data   
bob              data 
bob              data 
bob              data     
bob              data
bob   YES        data
bob              data 
bob              data 
jon              data

结果应该是： jon（因为有一次错误等于用户bob的是）

此代码不会省略所有bob。只省略一个：

SELECT USER FROM table1 WHERE wrong <> 'yes'

Answer 1

select user
from table1 a
where not exists (select 1 from table1 b where a.user = b.user and wrong = 'yes')

Answer 2

SELECT
    USER
FROM
    Mytable T1
WHERE
   NOT EXISTS (SELECT 3
       FROM Mytable T2
       WHERE T1.user = T2.User AND T2.Wrong = 'YES')

你也可以使用EXCEPT（标签说tsql），这给出了相同的计划

SELECT
    USER
FROM
    Mytable
EXCEPT
SELECT
    USER
FROM
    Mytable
WHERE
    Wrong = 'YES'

对于EXISTS的仇敌。假设USER列没有NULL，否则失败

SELECT
    USER
FROM
    Mytable T1
WHERE
   T1.USER NOT IN (SELECT T2.USER
       FROM Mytable T2
       WHERE T2.Wrong = 'YES')

Answer 3

SELECT *
FROM table1 t1
WHERE NOT EXISTS
  (SELECT 1
   FROM table1 t2
   WHERE t1.user = t2.user
   AND wrong = 'yes');

Answer 4

select user from table1 where wrong <> 'yes' group by user

如果一行等于某个值，则省略所有结果

4 个答案: