How to select the last 2-element group by a topic_id in MySQL

Posted by Luca Romagnoli on Stack Overflow See other posts from Stack Overflow or by Luca Romagnoli
Published on 2010-04-07T23:01:59Z Indexed on 2010/04/08 11:43 UTC
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Filed under:

sql

|

mysql

Hi i have to select the 2 lastest element for every topic

ex: table: msg

id  |   topic_id
-----------
1  |  1
2  |  1
3  |  1
4  |  1
5  |  2
6  |  2
7  |  2
8  |  3
9  |  3
   10  |  3

i want obtain these rows:

How can i do?

thanks

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