MySQL多重排序并忽略？

Question

如果有人想尝试这个，就做了一个测试sqlfiddle...

http://sqlfiddle.com/#!9/904e18/2/0

在我的数据库中我有这个:

Group: A
Name: A-1, Points: 7pts
Name: A-2, Points: 6pts
Name: A-3, Points: 6pts
Name: A-4, Points: 5pts

Group: B
Name: B-1, Points: 1pts
Name: B-2, Points: 5pts
Name: B-3, Points: 4pts
Name: B-4, Points: 6pts

Group: C
Name: C-1, Points: 6pts
Name: C-2, Points: 8pts
Name: C-3, Points: 9pts
Name: C-4, Points: 2pts

我需要首先按照得分最高的总体领先者对其进行排序。 (C-3)

然后我需要按第二总体领先者排序，但不在总体领先者组中排序。 (A-1)

接下来，我需要按第三总领导者排序，但不在总领导者或第二领导者的组中(B-4)

然后按点数对其余部分进行排序。

所以它应该是这样的:

C-3
A-1
B-4
^^各组的领导者，按从高到低排序
-----
然后剩下的按分数从高到低排列，没有群体特异性。

Answer 1

您可以通过以下查询以您想要的方式获取前 3 名球队:

select * from teams
where points = (select max(points) from teams as t where t.`group` = teams.`group`)
order by points desc

您还可以通过以下查询以您想要的方式获取其余团队:

select *  from teams
where name not in 
  (select name from teams
  where points = (select max(points) from teams as t where t.`group` = teams.`group`))
order by points desc

问题是，如果您合并这两个查询，那么您将丢失它们包含的任何顺序。因此，为了合并这 2 个结果，您必须在 2 个结果中添加 sortKey 并在最终结果的排序中使用它，以便保留订购。查询如下:

(select *, 1 as SortKey from teams
where points = (select max(points) from teams as t where t.`group` = teams.`group`))

UNION ALL

(select *, 2 as SortKey from teams
where name not in 
  (select name from teams
  where points = (select max(points) from teams as t where t.`group` = teams.`group`)))

order by SortKey, points desc

你也可以在这个sqlfiddle中看到它