如何通过MySQL中的另一个表对计算的SUM进行排序

Question

例如，我有2个表＆＃39; meta＆＃39;和＆＃39; log＆＃39;

在元表中：

| type | score |
|------|-------|
| a    | 1     |
| b    | 2     |
| c    | 3     |

在日志表中：

| log_id | log_type | object_id |
|--------|----------|-----------|
| 1      | a        | 13        | 
| 2      | b        | 13        |
| 3      | a        | 14        |
| 4      | c        | 14        |
| 5      | b        | 15        |
| 6      | c        | 15        |

所以我们知道：

object 13 got score: a+b = 3
object 14 got score: a+c = 4
object 15 got score: b+c = 5

我想按对象ID查询日志表组，并按对象得分的总和来查询，是否可以？

Answer 1

select log.object_id, sum(meta.score)
from log
left join meta on meta.type = log.log_type
group by log.object_id
order by sum(meta.score) desc

Answer 2

这将产生所需的输出

SELECT object_id, sum(score) from log 
INNER JOIN meta on meta.type = log.log_type group by object_id ORDER BY sum(score);

但你有正确的桌子设计吗？您需要加入meta.type和log.log_type列，但这意味着如果log_type是＆＃39; a＆＃39;对于所有object_id来说，3的值是常见的，这真的是你想要的吗？

Answer 3

试试这个

Select object_id,sum(score) as c FROM `log` as a INNER JOIN `meta` as b on a.log_type=b.type group by object_id order by c desc

Answer 4

SELECT log.object_id, sum(score) total_score
FROM meta
INNER JOIN log on meta.type = log.log_type
GROUP BY log.object_id