Why is there no == operator in SQL?

Why is there no == operator in SQL that yields true if both operands are either null or have the same value?

Here's the truth table for the = operator:

=	42	13	null
42	true	false	null
13	false	true	null
null	null	null	null

This has some implications. The statement

select * from t where col1 = col2

won't return a record where both col1 and col2 are null.

I suspect that in most cases this is not what the author of such a statement wants. Therefore, they will rewrite the query so:

select * from t where ( a is null and b is null) or ( a = b)

Now, if there were a == operator with this truth table:

==	42	13	null
42	true	false	false
13	false	true	false
null	false	false	true

it would definitely make my life easier (and would not cost the database companies too much money to implement).

Maybe I am all wrong and there is such a thing somewhere. If you know of such an operater in any database product, please let me know!