需要简单的SQL查询帮助

Question

我有这张桌子

uid  |  rid
-----------
1    |    4
1    |   13
2    |    4
3    |   13

我希望我的查询返回uid = 13且没有rid = 4的uid，因此结果应为3

到目前为止，我有

SELECT distinct uid
FROM test
WHERE 
ur.rid <> 4 
AND ur.rid = 13

但是当然这是返回1和3

我只想得到3个查询，我想念的是什么？

非常感谢。

Answer 1

您可以添加NOT EXISTS ：

SELECT DISTINCT uid
FROM test t1
WHERE t1.rid = 13
  AND NOT EXISTS (SELECT 1
                  FROM test t2
                  WHERE t2.uid = t1.uid
                    AND t2.rid = 4);

LiveDemo

或使用聚合：

SELECT uid
FROM test
GROUP BY uid
HAVING COUNT(CASE WHEN rid = 13 THEN 1 END) > 0
   AND COUNT(CASE WHEN rid = 4 THEN 1 END) = 0;

LiveDemo2

编辑（通过戈登）：

上面的答案很好。 我只是为了简化第二个查询而添加了它（似乎不适合单独输入答案，而且评论太长了）：

SELECT uid
FROM test
GROUP BY uid
HAVING SUM(rid = 13) > 0 AND
       SUM(rid = 4) = 0;

它利用了MySQL的一个不错的功能。

SqlFiddleDemo