On 9/6/06, George Pavlov <gpavlov@xxxxxxxxxxxxxx> wrote:
I have two columns, both individually nullable, but a row needs to have a value in one or the other. What is the best way to implement the constraints? I currently have: create table f ( a int, b int, check (a + b is null), check (coalesce(a,b) is not null) ); Is there a better way to do it?
Personally I woud simply put there CHECK(a IS NOT NULL OR b IS NOT NULL) which is probably the simplest form of your constraint. :)
