mysql query ordering by different column depending on value of another column

Question

I have tried this code but it is not working.

$select=$conn->query("select * from tbl_testquestion ORDER BY SUBSTRING( type_id=0 qu_id RAND() ) , type_id=1 qu_id ASC");

please suggest edit if question not reached the standards

Answer 1

you'll want to use a case statement

SELECT *      
FROM tbl_testquestion 
ORDER BY 
    CASE 
        WHEN type_id=0 THEN RAND() 
        WHEN type_id=1 THEN qu_id 
    END ASC