相关疑难解决方法(0)

MySQL是否有一种很好的方式来复制SQL Server功能ROW_NUMBER()？

例如:

SELECT 
    col1, col2, 
    ROW_NUMBER() OVER (PARTITION BY col1, col2 ORDER BY col3 DESC) AS intRow
FROM Table1

然后,我可以,例如,添加一个限制intRow为1 的条件,以获得col3每(col1, col2)对最高的单行.

我有这样一个数据库:

-------------------------------------------------------------------
|   id_one   |   id_two   |   timestamp_one   |   timestamp_two   |
-------------------------------------------------------------------
|     27     |     35     |        9:30       |        NULL       |
-------------------------------------------------------------------
|     35     |     27     |        NULL       |        9:35       |
-------------------------------------------------------------------
|     27     |     35     |        9:34       |        NULL       |
-------------------------------------------------------------------
|     35     |     27     |        NULL       |        9:33       |
-------------------------------------------------------------------

我需要拉4行

ORDER BY 'timestamp_one' if 'id_one'=27 or 
ORDER BY 'timestamp_two' if 'id_one'=27

这是我现在的声明:

SELECT * FROM tablename 
WHERE id_one=27 OR id_two=27 
ORDER BY 
  CASE WHEN id_one=27 THEN timestamp_one …