MySQL IN CLAUSE重复通缉

$sql = 'SELECT * FROM `courses` WHERE `id` IN ('. implode(",", $course[0]) .')';

This is the code I just had help with, I have used it before but the problem with it is, when something for example 1,1,2,3 is passed into the IN clause I will not get all values returned.

1x1 2x1 3x1

I want

1x2 2x1 3x1

All values must be returned otherwise it will mess up my table, any suggestions?

You won't be able to do that in SQL. Query by id and then use whatever language your are using to to do the 'multiplication'.