还是问一个mysql的查询汇总的汇总有关问题

程序员文章站 2022-05-11 08:53:45

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还是问一个mysql的查询汇总的汇总问题

本帖最后由 setoy 于 2013-12-18 18:11:02 编辑有五个人，uid分别是1～5
有对着这五个人打分的表格（某个人有可能没有得到过分数）

id  uid  scroe
-------------
1    1    1.5
2    1    1.8
3    2    -5.5
4    1    0.8
5    2    8.2
6    1    -2
7    4    3
8    2    2.3
--------------

现在要统计他们所有人的分数，即使查询不到某个人的得分，也要显示0分，显示格式如下：

用户  分数   汇总分
-----------------------
1      1.5     2.1
1      1.8     2.1
1      0.8     2.1
1      -2      2.1
2      -5.5    5
2      8.2     5
2      2.3     5
3      0       0
4      3       3
5      0       0

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------解决方案--------------------
问题是你数据集里都没uid=3和uid=5的纪录。参考

select t.*,round(s.scroe,1) as scroe , round(if(s.total is null,0,s.total),1) as summary from 
(select 1 as uid 
union 
select 2 as uid
union
select 3 as uid 
union 
select 4 as uid
union 
select 5 as uid) t left join 
(select uid,scroe,(select sum(scroe) from a where uid=aa.uid group by uid) as total from a as aa) s
on s.uid = t.uid

------解决方案--------------------

用户表tu

得分表t

SQL：SELECT tu.uid,t.score,a.total from test t right join test_user tu on tu.uid=t.uid left join (SELECT uid,sum(score) as total from test group by uid) a on a.uid=t.uid order by tu.uid

结果