Question

假设我有3个表格，如下所示：

用户

oauth_uid | name
1         | John Claude
2         | Nick Jonas
3         | Justin Timberlake

测试

oauth_id | score
1        | 30
2        | 28
1        | 20
3        | 18
2        | 34

训练

oauth_id | score
2        | 3
1        | 8
1        | 2
2        | 18

我想按以下条件订购用户：

从测试ID中选择用户的最高分数为test_score
从训练中选择用户所有得分的总和为tr_score
最后添加以上两个并按降序排列

到目前为止，我已经能够满足前两个条件：

select test.oauth_id, max(test.score) as score, users.name
from users inner join
     test
     on test.oauth_id = users.oauth_uid
group by test.oauth_id
order by score desc

select sum(training.score) as tr_score
from training
group by training.oauth_id
order by tr_score desc

如何添加两者并按总分进行排序？

Answer 1

使用子查询：

select u.*, max_score, sum_score,
       (coalesce(max_score, 0) + coalesce(sum_score, 0)) as overall_score
from users u left join
     (select oauth_id, max(score) as max_score
      from test
      group by oauth_id
     ) te
     on te.oauth_id = u.oauth_id left join
     (select oauth_id, sum(score) as sum_score
      from test
      group by oauth_id
     ) tr
     on tr.oauth_id = u.oauth_id
order by overall_score desc;

添加两列并对其进行排序

1 个答案: