Subject Re: check if a select return value
Author Svein Erling
> When I don't assign any value to a variable, the default value for
> integer are null ? and for varchar? where can I see the default
> value for the types?

No, it is not a value at all. NULL is a state meaning that the value is unknown. All types can be unknown, and NULL differ from any value in that whatever you compare it to, it returns NULL. The same goes for any assignment, NULL + 5 is still NULL (if you did not know how much money you had in your wallet, you still don't know how much you have after putting some more money into it).