如果列的SUM达到某个数字，则返回行

Question

这是mybb_reputation表

如果所有这些行的rid总和达到3，我想获取行reputation的数量。例如，在这种情况下（请参见上图）如果我运行一个查询它应该返回除1,2和3（所以总声誉变为3）或者它只返回rid 5，因为它的声誉正好等于3

我尝试过运行此查询;

SELECT * FROM mybb_reputation WHERE SUM(reputation) = 3;

但由于MySQL知识有限，显示错误，例如：＃1111 - 无效使用群组功能

请帮忙！

Answer 1

这个答案与我的评论有关 -

查找1条记录（简单）

SELECT tmp1.rid AS rid
FROM mybb_reputation AS tmp1
WHERE tmp1.reputation = 3;

查找任意2条记录（使用＆lt;因为关系的顺序与答案无关）

SELECT CONCAT_WS(',',tmp1.rid, tmp2.rid) AS rid
FROM mybb_reputation AS tmp1
JOIN mybb_reputation AS tmp2
  ON tmp1.rid < tmp2.rid
WHERE tmp1.reputation + tmp2.reputation = 3

查找任何3条记录（与之前相同的想法＆lt;）

SELECT CONCAT_WS(',',tmp1.rid, tmp2.rid, tmp3.rid) AS rid
FROM mybb_reputation AS tmp1
JOIN mybb_reputation AS tmp2
  ON tmp1.rid < tmp2.rid
JOIN mybb_reputation AS tmp3
  ON tmp2.rid < tmp3.rid
WHERE tmp1.reputation + tmp2.reputation + tmp3.reputation = 3

查找4（算法重复）

SELECT CONCAT_WS(',',tmp1.rid, tmp2.rid, tmp3.rid, tmp4.rid) AS rid
FROM mybb_reputation AS tmp1
JOIN mybb_reputation AS tmp2
  ON tmp1.rid < tmp2.rid
JOIN mybb_reputation AS tmp3
  ON tmp2.rid < tmp3.rid
JOIN mybb_reputation AS tmp4
  ON tmp3.rid < tmp4.rid
WHERE tmp1.reputation + tmp2.reputation + tmp3.reputation + tmp4.reputation = 3

您需要为所需的许多组合继续此操作。

Answer 2

SELECT *
FROM mybb_reputation
GROUP BY uid
HAVING SUM(reputation) >= 3
ORDER BY RAND()
LIMIT 1

不确定这个的确切顺序，但它应该包含您需要的所有条件。

老实说，你的数据结构似乎很奇怪，无法回答这些问题。

Answer 3

您可能希望获得组的总和。我打算假设你想通过uid分组：

SELECT * FROM mybb_reputation 
WHERE uid in 
  (Select uid FROM mybb_reputation
   GROUP BY uid
   HAVING SUM(reputation) = 3);

如果要选择与某些聚合条件匹配的各个行，则需要子查询。嵌套子查询查找具有所需条件的组。然后外部查询说返回该组中的每一行。必须以某种方式识别该组，在这种情况下，我们使用uid。

MySQL的某些实现会将此视为相关子查询，如果您的表很大，这可能是一个问题。如果您遇到此问题，可以再添加一个subselect图层来修复它：

SELECT * FROM mybb_reputation 
WHERE uid in 
  (SELECT * FROM
     (Select uid FROM mybb_reputation
      GROUP BY uid
      HAVING SUM(reputation) = 3));

或使用连接而不是子查询：

SELECT r1.* FROM mybb_reputation r1,
     (Select uid FROM mybb_reputation
      GROUP BY uid
      HAVING SUM(reputation) = 3) r2
WHERE r1.uid = r2.uid;

Answer 4

试试这个

SELECT * FROM mybb_reputation GROUP BY rid HAVING SUM(reputation) = 3 ORDER BY RAND() LIMIT 1;