SQL: Pick highest and lowest value (int) from one row - sql

Question

I am looking for a way to pick the highest and lowest value (integer) from a single row in table. There are 4 columns that i need to compare together and get highest and lowest number there is.
The table looks something like this...
id | name | col_to_compare1 | col_to_compare2 | col_to_compare3 | col_to_compare4
1 | John | 5 | 5 | 2 | 1
2 | Peter | 3 | 2 | 4 | 1
3 | Josh | 3 | 5 | 1 | 3
Can you help me, please? Thanks!

Answer 1

You can do this using CROSS APPLY and the VALUES clause. Use VALUES to group all your compared columns and then select the max.
SELECT
MAX(d.data1) as MaxOfColumns
,MIN(d.data1) as MinOfColumns
,a.id
,a.name
FROM YOURTABLE as a
CROSS APPLY (
VALUES(a.col_to_compare1)
,(a.col_to_compare2)
,(a. col_to_compare3)
,(a.col_to_compare4)
,(a. col_to_compare5)
) as d(data1) --Name the Column
GROUP BY a.id
,a.name

Answer 2

Assuming you are looking for min/max per row
Declare #YourTable table (id int,name varchar(50),col_to_compare1 int,col_to_compare2 int,col_to_compare3 int,col_to_compare4 int)
Insert Into #YourTable values
(1,'John',5,5,2,1),
(2,'Peter',3,2,4,1),
(3,'Josh',3,5,1,3)
Select A.ID
,A.Name
,MinVal = min(B.N)
,MaxVal = max(B.N)
From #YourTable A
Cross Apply (Select N From (values(a.col_to_compare1),(a.col_to_compare2),(a.col_to_compare3),(a.col_to_compare4)) N(N) ) B
Group By A.ID,A.Name
Returns
ID Name MinVal MaxVal
1 John 1 5
3 Josh 1 5
2 Peter 1 4

Answer 3

These solutions keep the current rows and add additional columns of min/max.
select *
from t cross apply
(select min(col) as min_col
,max(col) as max_col
from (
values
(t.col_to_compare1)
,(t.col_to_compare2)
,(t.col_to_compare3)
,(t.col_to_compare4)
) c(col)
) c
OR
select *
,cast ('' as xml).value ('min ((sql:column("t.col_to_compare1"),sql:column("t.col_to_compare2"),sql:column("t.col_to_compare3"),sql:column("t.col_to_compare4")))','int') as min_col
,cast ('' as xml).value ('max ((sql:column("t.col_to_compare1"),sql:column("t.col_to_compare2"),sql:column("t.col_to_compare3"),sql:column("t.col_to_compare4")))','int') as max_col
from t
+----+-------+-----------------+-----------------+-----------------+-----------------+---------+---------+
| id | name | col_to_compare1 | col_to_compare2 | col_to_compare3 | col_to_compare4 | min_col | max_col |
+----+-------+-----------------+-----------------+-----------------+-----------------+---------+---------+
| 1 | John | 5 | 5 | 2 | 1 | 1 | 5 |
+----+-------+-----------------+-----------------+-----------------+-----------------+---------+---------+
| 2 | Peter | 3 | 2 | 4 | 1 | 1 | 4 |
+----+-------+-----------------+-----------------+-----------------+-----------------+---------+---------+
| 3 | Josh | 3 | 5 | 1 | 3 | 1 | 5 |
+----+-------+-----------------+-----------------+-----------------+-----------------+---------+---------+

Answer 4

A way to do this is to "break" apart the data
declare #table table (id int, name varchar(10), col1 int, col2 int, col3 int, col4 int)
insert into #table values (1 , 'John' , 5 , 5 , 2 , 1)
insert into #table values (2 , 'Peter' , 3 , 2 , 4 , 1)
insert into #table values (3 , 'Josh' , 3 , 5 , 1 , 3)
;with stretch as
(
select id, col1 as col from #table
union all
select id, col2 as col from #table
union all
select id, col3 as col from #table
union all
select id, col4 as col from #table
)
select
t.id,
t.name,
agg.MinCol,
agg.MaxCol
from #table t
inner join
(
select
id, min(col) as MinCol, max(col) as MaxCol
from stretch
group by id
) agg
on t.id = agg.id

Answer 5

Seems simple enough
SELECT min(col1), max(col1), min(col2), max(col2), min(col3), max(col3), min(col4), max(col4) FROM table
Gives you the Min and Max for each column.
Following OP's comment, I believe he may be looking for a min/max grouped by the person being queried against.
So that would be:
SELECT name, min(col1), max(col1), min(col2), max(col2), min(col3), max(col3), min(col4), max(col4) FROM table GROUP BY name