use if-else logic in where clause in T-SQL

Question

Is there any way to use if-else logic in where clause in T-SQL? or do I have to implement the logic by using subquery?

Answer 1

Use Case

(case foo when bar then baz else fizz end)

Answer 2

You can use a case statement in a where clause, but it can generate performance issues, so you may want to try a different approach if you have a large dataset. A correlated subquery would not be a good alternative approach; a derived table or CTE might be.