Question

I have a table like this

id | a | b | c | status
---+---+---+---+--------
1  | 3 |12 |6  |   b
2  | 5 |8  |56 |   c
3  | 99|7  |23 |   a

I would like to detect which column has the greatest value (1,2 or 3) and then record the “status” of that row highest value (I used a,b,c just for the example)

How could I do this?

Thanks!

Answer 1

SELECT *, 
    CASE GREATEST(a,b,c)
        WHEN a THEN 'a'
        WHEN b THEN 'b'
        WHEN c THEN 'c'
    END AS status
FROM yourtable

See it working online: sqlfiddle

Rewritten as an UPDATE statement:

UPDATE yourtable
SET status =
    CASE GREATEST(a,b,c)
        WHEN a THEN 'a'
        WHEN b THEN 'b'
        WHEN c THEN 'c'
    END