选择一列中相同值的第一行

Question

我在名为message的表中有这些值：

id       message_id      message
1             1            Hello sir
2             1            Hi dear.
3             2            Send by admin.
4             2            send by helper. 
5             3            created by me. 
6             3            Done by user.

我的结果是下面的表格。

id       message_id      message
1             1            Hello sir
3             2            Send by admin. 
5             3            created by me. 

请帮助。

Answer 1

你可以尝试，只需使用一个选择唯一值的distinct子句。

SELECT DISTINCT * from meassage;

Answer 2

select M.id, M.message_id, M.message 
from message M
WHERE  M.ID = (SELECT MIN(M1.ID) FROM MESSAGE M1 WHERE M1.MESSAGE_ID = M.MESSAGE_ID) ;