How to replicate MIN and MAX in SQL - sql-server

Question

I have an excel formula that I need to recreate in SQL:
=MIN(150,0.75*MAX(100-0-0/0.9,0))
It can be done with nested case statements, but I am using a program to generate SQL which currently does not support this:
select
case
when 150 <
case
when 0.75*100-0-0/0.9 < 0
THEN 0
ELSE 0.75*100-0-0/0.9
END
THEN 150
ELSE 0.75*100-0-0/0.9
END
Is there another way of doing this without creating a stored procedure?
Please note: I cannot use any new functionality from SQL Server 2012 or onwards.

Answer 1

MIN and MAX in SQL Server don't work with a delimited list; they get to minimum/maximum value for an expression across a dataset. Thus, there's no such functionality as SELECT MIN(ColumnA, ColumnB, ColumnC);, instead you'd have something like:
WITH Numbers AS(
SELECT *
FROM (VALUES (1),(2),(3)) V(N)
)
SELECT MAX(N), MIN(N)
FROM Numbers;
If you need to get the MAXIMUM between columns, then yes, you'll need to use a CASE expression. Using your data, and a bit of giuess work, this results in something like:
WITH Numbers AS(
SELECT *
FROM (VALUES (150,0.75,100-0-0,0.9,0)) V(A,B,C,D,E))
SELECT CASE WHEN 150 > CASE WHEN C/D > E THEN C/D
ELSE E END THEN 150
ELSE CASE WHEN C/D > E THEN C/D
ELSE E END
END AS MaxN
FROM Numbers;
The other alternative, would be to pivot your data, and get the MAX/MIN that way. I've not posted a solution here for that one though, as we only have constants to work with, and I don't want to guess an answer.

Answer 2

Try to use subqueries with UNION ALL
SELECT MIN(Value)
FROM
(
SELECT 150 Value
UNION ALL
SELECT 0.75*MAX(Value)
FROM
(
SELECT 100-0-0/0.9 Value
UNION ALL
SELECT 0
) q
) q
And this query with variables
DECLARE
#value1 float=100-0-0/0.9,
#value2 float=0,
#value3 float=150
SELECT MIN(Value)
FROM
(
SELECT #value3 Value
UNION ALL
SELECT 0.75*MAX(Value)
FROM
(
SELECT #value1 Value
UNION ALL
SELECT #value2
) q
) q