Problem in finding next / previous row in mysql

Question

SELECT id ,MAX(status) AS status FROM Mail WHERE 
     status < (SELECT status FROM Mail WHERE id = 1000) 
     GROUP BY status ORDER BY status DESC LIMIT 1;

I am using this query to find the previous row of the current row 1000.Here i am getting NULL values if i use the status column which is not unique.where as it gives proper values if i use unique columns.

Answer 1

Try this:

SELECT m1.id, MAX(m1.status) AS 'status' FROM Mail m1, Mail m2
WHERE m1.status < m2.status AND m2.id = 1000
GROUP BY m1.status ORDER BY m1.status DESC LIMIT 1;