Minimum values from the table - mysql

Question

I need the minimum value from 3 coloumn and corresponding name for the min value,
like this..
Name val1 val2 val3
a 12 5 4
b 10 9 1
c 7 11 5
d 13 8 2
output:
Name MIN
b 1
I wrote query to find minimum value :
select MIN(less)
from (
select case
when val1<=val2 and val1<=val3 then val1
when val2<=val1 and val2<=val3 then val2
when val3<=val1 and val3<=val2 then val3 end as less from table) as low
I used alises,i want to display the corresponding name from the table...plz tell me the query...

Answer 1

You can do it using the UNION operator to convert the 3 column table into a single table with 1 column.
SELECT TOP 1 Name, Val AS Min
FROM (
SELECT Name, val1 AS Val
FROM table
UNION
SELECT Name, val2 AS Val
FROM table
UNION
SELECT Name, val3 AS Val
FROM table
) AS sub_query
ORDER BY Val ASC
This solution has the added advantage that it is easier to maintain if the number of columns increases.

Answer 2

Most Concise
SELECT top 1 Name,col,val
FROM T
UNPIVOT ( val for col in (val1,val2,val3)) unpvt
ORDER BY val
Most Efficient (assuming these columns are indexed)
;WITH cte(Name, col, val) AS
(
SELECT TOP 1 Name, 'val1', val1
FROM T
ORDER BY val1
UNION ALL
SELECT TOP 1 Name, 'val2', val2
FROM T
ORDER BY val2
UNION ALL
SELECT TOP 1 Name, 'val3', val3
FROM T
ORDER BY val3
)
SELECT TOP 1 Name, col, val
FROM cte
ORDER BY val