Question

所以我有这个游戏数据库，我有几个用户有字段，id，名称，点

我需要一个特定用户的排名表，其位置可以看到与点数相关，表中有8个位置的空间，所以我正在寻找一种方法来执行以下操作：

如果我SELECT * FROM users WHERE id = {user_id} ORDER By points选择之前的4个结果和此ID之后的3个结果。有这样的查询吗？结果应该如下：

---------------------
|id   |name  |points|
---------------------
| 52  |name1 | 10   |
---------------------
| 23  |name1 | 09   |
---------------------
| 93  |name1 | 08   |
---------------------
| 12  |name1 | 07   |
---------------------
| 43  |queried_name1 | 06   |
---------------------
| 67  |name1 | 05   |
---------------------
| 32  |name1 | 04   |
---------------------
| 91  |name1 | 03   |
---------------------

我试图通过软件来实现这一点但是通过所有结果迭代它是相当慢的。谢谢你的帮助！

Answer 1

就像上面的结果一样，我会这样说：

SELECT * FROM users WHERE points > (SELECT points FROM users WHERE id = {user_id}) ORDER By points ASC LIMIT 3;

以下结果：

SELECT * FROM users WHERE points < (SELECT points FROM users WHERE id = {user_id}) ORDER By points DESC LIMIT 4;

所以，通过一个大联盟，它会给出：

SELECT * FROM (SELECT * FROM users WHERE points > (SELECT points FROM users WHERE id = {user_id}) ORDER By points ASC LIMIT 3 ) a 
UNION
SELECT * FROM users WHERE id = {user_id}
UNION
SELECT * FROM (    SELECT * FROM users WHERE points < (SELECT points FROM users WHERE id = {user_id}) ORDER By points DESC LIMIT 4 ) b

Answer 2

您可以使用此查询 -

SELECT id, name, points FROM (
  SELECT u.*, @r:=@r+1 rank, @pos:=IF(@pos = 0 AND name = 'queried_name1', @r, @pos)
    FROM users u,
    (SELECT @r:=0, @pos:=0) t
  ORDER BY points DESC
  ) t
WHERE rank BETWEEN @pos - 4 AND @pos + 3

它按点对表进行排名，找到name ='queried_name1'的记录，并在找到的记录之前和之后选择一些行。

使用MySQL ORDER BY选择范围

2 个答案: