What Is a Check Constraint?

A check constraint is a way to do something similar to a rail's a act of record model validation would do. A foreign key will make sure that, if you reference the i d from another table, on a source table, that that row is a post cris. It won't allow you to delete that other row that is referenced by that foreign key. And poscras there i sm additional constraint types like that you are probably familiar with, like primary key.