Question

I want use ORDER BY RAND() query mysql. But I have some question want to ask.

my mysql table ‘image’ like:

id | image | width | height |
1  | 1.jpg | 640   | 480    |
2  | 2.jpg | 800   | 600    |
3  | 3.jpg | 480   | 600    |
4  | 4.jpg | 720   | 480    |
5  | 5.jpg | 600   | 800    |
6  | 6.jpg | 1024  | 768    |
7  | 7.jpg | 768   | 1024   |
8  | 8.jpg | 800   | 600    |
9  | 9.jpg | 720   | 560    |
10 | 10.jpg| 800   | 600    |

I need do a mysql query ORDER BY RAND() print 5 images, the orders are:

first: width >= 720 and height >= 560 , 1 image(this may be width < height)

second: width > height, 2 images.(left the first 1 image, do the rest 9 images ORDER BY RAND())

third: width >= 640, 2 images.(left above 3 images, do the rest 7 images ORDER BY RAND())

all the 5 images no repeat. My mind are confused now, need a help.

Answer 1

Well, if I understand your question correctly you want to do something like

(SELECT image FROM tab WHERE(first) ORDER BY RAND() LIMIT 1)
UNION
(SELECT image FROM tab WHERE(second) ORDER BY RAND() LIMIT 2)
UNION
(SELECT image FROM tab WHERE(third) ORDER BY RAND() LIMIT 2)

In the each WHERE clause replace the first, second and third with correct constraints…