每月前5名（月份是varchar）

Question

假设我有这张表

article | score | date (VARCHAR)
A           10      2010/01
B           10      2010/01
C           10      2010/01
D           10      2010/01
E           10      2010/01
F            1      2010/01
G            1      2010/01
H            1      2010/01
B            9      2010/01
B            9      2010/01
A            4      2010/02
C           10      2010/02
G           10      2010/02
G            2      2010/02

我会以不同的日期返回TOP 5分数。

我喜欢的输出：

article |  average |  date
A            10       2010/01
B           9.33      2010/01
C            10       2010/01
D            10       2010/01
E            10       2010/01
A            4        2010/02
....        ...        .....

我尝试了一些结果很少的查询。

SELECT
    article as articlex,
    date as datex,
    (SELECT avg(score) FROM test_anna WHERE article = articlex AND date = datex) as average
FROM test_anna GROUP BY articlex, average ORDER BY datex ASC, articlex ASC

如何使用mysql语句执行此操作？ 谢谢！

Answer 1

一种方法使用row_number()或rank()（取决于您希望如何处理关系）：

select t.*
from (select t.*,
             row_number() over (partition by date order by score desc) as seqnum
      from test_anna t
     ) t
where seqnum <= 5;