Max and min from the column in a table - sql-server

Question

i have a table with the following data, i am trying to get the max and min columns from the table. if it is one column i can use max/min for the column, but here i am comparing all the column in a table. what i need is add new columns to store max and min data.
and there will be only one row in the table
create table
#test ( column1 int, column2 int , column3 int , column4 int ,column5 int,column6 int)
insert into #test
values( 89, 103,87,67,86,56)
select * from #test
--drop table #test
thanks in advance.

Answer 1

The easiest way to do this is just cross applying the min/max values of the columns. For example:
SELECT *
FROM #test t
CROSS APPLY (
SELECT MAX(val), MIN(val)
FROM (VALUES (t.column1), (t.column2), (t.column3), (t.column4), (t.column5), (t.column6)) AS c(val)
) AS c(maxvalue, minvalue);

Answer 2

Using the VALUES method to unpivot the data and then reaggravating it will make for a cleaner syntax but it does come with a cost to performance (not terrible but it is there). Using CASE expressions is a bit more cumbersome but in the syntax department, especially if there a lot of columns to be evaluated, but you won't incur the same performance penalty...
SELECT
t.column1, t.column2, t.column3, t.column4, t.column5, t.column6,
MinValue = CASE
WHEN t.column1 <= t.column2 AND t.column1 <= t.column3 AND t.column1 <= t.column4 AND t.column1 <= t.column5 AND t.column1 <= t.column6 THEN t.column1
WHEN t.column2 <= t.column1 AND t.column2 <= t.column3 AND t.column2 <= t.column4 AND t.column2 <= t.column5 AND t.column2 <= t.column6 THEN t.column2
WHEN t.column3 <= t.column1 AND t.column3 <= t.column2 AND t.column3 <= t.column4 AND t.column3 <= t.column5 AND t.column3 <= t.column6 THEN t.column3
WHEN t.column4 <= t.column1 AND t.column4 <= t.column2 AND t.column4 <= t.column3 AND t.column4 <= t.column5 AND t.column4 <= t.column6 THEN t.column4
WHEN t.column5 <= t.column1 AND t.column5 <= t.column2 AND t.column5 <= t.column3 AND t.column5 <= t.column4 AND t.column5 <= t.column6 THEN t.column5
ELSE t.column6
END,
MaxValue = CASE
WHEN t.column1 >= t.column2 AND t.column1 >= t.column3 AND t.column1 >= t.column4 AND t.column1 >= t.column5 AND t.column1 >= t.column6 THEN t.column1
WHEN t.column2 >= t.column1 AND t.column2 >= t.column3 AND t.column2 >= t.column4 AND t.column2 >= t.column5 AND t.column2 >= t.column6 THEN t.column2
WHEN t.column3 >= t.column1 AND t.column3 >= t.column2 AND t.column3 >= t.column4 AND t.column3 >= t.column5 AND t.column3 >= t.column6 THEN t.column3
WHEN t.column4 >= t.column1 AND t.column4 >= t.column2 AND t.column4 >= t.column3 AND t.column4 >= t.column5 AND t.column4 >= t.column6 THEN t.column4
WHEN t.column5 >= t.column1 AND t.column5 >= t.column2 AND t.column5 >= t.column3 AND t.column5 >= t.column4 AND t.column5 >= t.column6 THEN t.column5
ELSE t.column6
END
FROM
#test t;
Results...
column1 column2 column3 column4 column5 column6 MinValue MaxValue
----------- ----------- ----------- ----------- ----------- ----------- ----------- -----------
89 103 87 67 86 56 56 103

Answer 3

I found this solution here.
SELECT
column1
,column2
,column3
,column4
,column5
,column6
,(SELECT MAX(MaxValue)
FROM (VALUES (column1),(column2),(column3), (column4), (column5), (column6)) AS [Values](MaxValue))
AS MaxValue
,(SELECT MIN(MinValue)
FROM (VALUES (column1),(column2),(column3), (column4), (column5), (column6)) AS [Values](MinValue))
AS MinValue
FROM #test