I need a check constraint on two columns, at least one must be not null

Question

I have a table in SQL Server with two numeric columns. At least one of these numeric fields must be filled. How do I write a check constraint to verify this?

Answer 1

late answer, but here is a solution for Sql Server for any number of columns to check:

CONSTRAINT CK_one_is_not_null CHECK (COALESCE(col1, col2, col3) IS NOT NULL )