Trouble with aggregate in Where clause, Selecting Max(x) When Max(x) != 3 - sql

Question

I am trying to reconfigure the below sql to only pull records when the Max(Field) != 3 but keep getting an error (detailed) below.
This is the code before adding the Where Max(field) != 3
SELECT P.Code,
MAX(PW.v1) AS V1
FROM SW
INNER JOIN S ON SW.S_Id = S.Id
INNER JOIN PW ON SW.PW_Id = PW.Id
INNER JOIN PON S.P_Id = P.id
WHERE S.P_Id = P.id
GROUP BY P.Code
My Attempt
SELECT P.Code,
MAX(PW.v1) AS V1
FROM SW
INNER JOIN S ON SW.S_Id = S.Id
INNER JOIN PW ON SW.PW_Id = PW.Id
INNER JOIN PON S.P_Id = P.id
WHERE S.P_Id = P.id
AND (SELECT MAX(PW.v1)
FROM SW AS SW2
WHERE SW.PWId = SW2.PW_Id) != 3
GROUP BY P.Code
This is the error I get and not sure what to do:
An aggregate may not appear in the WHERE clause unless it is in a subquery contained in a HAVING clause or a select list, and the column being aggregated is an outer reference.

Answer 1

Traditional method of filtering on results of an aggregate can be achieved by using HAVING clause. I also removed the unnecessary WHERE clause as you already joined those 2 tables on that column. Here is the query:
SELECT P.Code
,MAX(PW.v1) AS V1
FROM SW
INNER JOIN S
ON SW.S_Id = S.Id
INNER JOIN PW
ON SW.PW_Id = PW.Id
INNER JOIN P
ON S.P_Id = P.id
GROUP BY P.Code
HAVING MAX(PW.v1)!=3;