Question

我在MS SQL Server Management Studio中有这个表

+------+-----------+--------
| id   | client id | bla bla blaaaa
+------+-----------+--------
|    1 |   1       | .......
|    2 |   2       | .......
|    3 |   3       | .......
|    4 |   8       | .......
|    5 |   9       | .......
|    6 |   15      | .......
|    7 |   1       | .......
|    8 |   16      | .......
|    9 |   2       | .......
|   10 |   9       | .......
|   12 |   12      | .......
+------+-----------+--------

我需要获得最大值为[id]的唯一[客户端ID]，如此

+------+-----------+--------
| id   | client id | bla bla blaaaa
+------+-----------+--------
|    3 |   3       | .......
|    4 |   8       | .......
|    6 |   15      | .......
|    7 |   1       | .......
|    8 |   16      | .......
|    9 |   2       | .......
|   10 |   9       | .......
|   12 |   12      | .......
+------+-----------+--------

我试过这段代码，但效果不好..有人能帮助我吗？

SELECT *
FROM   table AS one 
INNER JOIN table AS two
   ON one.[client id] = two.[client id]
   WHERE one.[id] > two.[id]

Answer 1

SELECT max(id), client_id, blah_blah
FROM my_table
GROUP BY client_id, blah_blah

SQL，获取列的最大ID

1 个答案: