Question

I have some table restore user articles. the table struction like…

id | uid | imgae |
1  |  1  | 1.jpg |
2  |  1  |       |
3  |  2  | 2.jpg |
4  |  3  | 3.jpg |
5  |  3  |       |
6  |  3  | 4.jpg |
7  |  4  |       |
...

Then I want get 10 result witch image!=''

(select * from my_table where image!='' order by rand() limit 1)
UNION 
(select * from my_table where image!='' order by rand() limit 1)
UNION 
(select * from my_table where image!='' order by rand() limit 1)
UNION 
(select * from my_table where image!='' order by rand() limit 1)
UNION 
(select * from my_table where image!='' order by rand() limit 1)
UNION 
(select * from my_table where image!='' order by rand() limit 1)
UNION 
(select * from my_table where image!='' order by rand() limit 1)
UNION 
(select * from my_table where image!='' order by rand() limit 1)
UNION 
(select * from my_table where image!='' order by rand() limit 1)
UNION 
(select * from my_table where image!='' order by rand() limit 1)

And how to make a further query. 10 result with 10 different uid (a.uid!=b.uid)? And the code is too long… Any easy way? Thanks.

Answer 1

Change the limit and include a group by :

select * from my_table where image!='' order by rand() group by uid limit 10