Conditional Check in Where clause

Question

i have a procedure in which the below condition is to be written in a WHERE clause. How do I do that.

itemid is a parameter which can be null.

if itemid is avail

Answer 1

e.g.

SELECT Something
FROM SomeTable
WHERE (@MyParam IS NULL OR SomeField = @MyParam)
    AND AnotherField = 1

You'll want to test this in your specific scenario for performance. If it's a simple query i.e. without a lot of conditional parameters, you might want to try this instead for performance:

IF ( @MyParam IS NULL )
    SELECT Something
    FROM SomeTable
    WHERE AnotherField = 1
ELSE
    SELECT Something
    FROM SomeTable
    WHERE SomeField = @MyParam 
        AND AnotherField = 1