On Tuesday, January 24, 2023, Ryan Murphy <
ryanmurf@gmail.com> wrote:
SELECT NULL - date '2023-01-05';
-> result is null
SELECT NULL + date '2023-01-05';
-> result is [42725] ERROR: operator is not unique: unknown + date Hint: Could not choose a best candidate operator. You might need to add explicit type casts. Position: 13
There is no bug here.
I would expect both of those to be null.
I get why you expect that but we expend little to no effort to handle null in a type agnostic way. Type inference has to happen first and regardless of whether the literal is null. Type inference failed in the + case but not the - case. That is just happenstance of what operators happen to exist in the system.
David J.
