Wildcard empty variable query generator

Question

Hi all,
I am using the typical [%1] variables in the query generator.  However, my latest query needs to have many different variable parameters and I would like to leave some of them blank.
For example, the parameters are:
Warehouse Code [%0]
Item Group [%1]
Unit (UDF) [%2]
Row (UDF) [%3]
Column (UDF) [%4]
Problem is... I want to be able to leave some of the parameters blank and I don't want the system to filter by that parameter at all.
SO if I just want to put warehouse code in, then all the other parameters should be *.  Or if i want to use item group and row, then all the others will be *.  Right now I have to enter exactly what i want from all parameters, so it doesn't work very well.  I figured this wouldn't be so difficult.
Any suggestions?
M

Answer 1

Thanks guys, my final code was kind of a mish mash.  Works where if you don't enter any variables you will see the entire list of serialized items unfiltered, if you want to sort by location (unit, column, row, warehouse) then you can enter them as needed.
SELECT
T0.[IntrSerial],
T1.[ItemCode],
T1.[ItemName],
T2.[ItmsGrpNam] as 'Item Group Name',
T1.[ItmsGrpCod] as 'Item Group Code',
T1.[U_Unit],
T1.[U_Row],
T1.[U_Col],
T3.[WhsName],
T0.[WhsCode]
FROM OSRI T0 
INNER JOIN OITM T1 ON T0.ItemCode = T1.ItemCode
INNER JOIN OITB T2 ON T1.ItmsGrpCod = T2.ItmsGrpCod
INNER JOIN OWHS T3 ON T0.WhsCode = T3.WhsCode
WHERE
((T3.[WhsName] ='[%0]') OR ('[%0]'=''))
AND
((T2.[ItmsGrpNam] ='[%1]') OR ('[%1]'=''))
AND
((T1.[U_Unit] ='[%2]') OR ('[%2]' IS NULL) OR ('[%2]'=''))
AND
((T1.[U_Row] ='[%3]') OR ('[%3]' IS NULL) OR ('[%3]'=''))
AND
((T1.[U_Col] ='[%4]') OR ('[%4]' IS NULL) OR ('[%4]'=''))
ORDER BY
T1.[ItmsGrpCod],
T1.[ItemCode]
The where clauses allow you to leave the variable blank if you want, which is very handy!  I know I will use this code again.