Hello, Given the following table, I would like to ensure that all the rows for an email that have a user defined map to the same user.
CREATE TABLE person ( id INTEGER PRIMARY KEY, user TEXT, email TEXT NOT NULL); What I think I'm looking for is something like this: CREATE TABLE person ( id INTEGER PRIMARY KEY, user TEXT, email TEXT NOT NULL, EXCLUDE (email WITH =, user WITH <>) WHERE (user IS NOT NULL)); The not equals comparison isn't supported, but it would be useful here. Is there another way to do this, short of creating a separate table that associates email and user?