SQL IN, which is guaranteed to be false

Question

Is there any value that I can put in the SQL IN clause that guarantees that the clause will be evaluated as false?

SELECT * FROM Products WHERE ProductID IN (???) 

Is there anything that I could replace ??? with a guarantee that no rows will be returned?

Answer 1

Replace with NULL . There is no better guarantee!

Because no other value can be equal to NULL , even NULL .

And this is a kind of universal value for any type (as mentioned in @ zohar-peled).

Answer 2

Use NULL

 SELECT * FROM Products WHERE ProductID IN (NULL) 

Since it will not return anything

Answer 3

Put some initially invalid ProductID, for example. -1 .

 SELECT * FROM Products WHERE ProductID IN (-1) 

Answer 4

Try

 SELECT * FROM Products WHERE ProductID IN (0) 

I am sure that you do not have a product with ID = 0

This will return false.

Answer 5

 SELECT * FROM Products WHERE ProductID IN (SELECT '') 

Another possible way.