I spent the better part of today struggling with Rails while upgrading some old code. Documenting this here in order to hopefully save others the time.
In a case where you have three tables, e.g.
DungeonWizard is the join table, you cannot make the foreign keys in
DungeonWizard constrained to not null.
In the below code, if you run these statements:
The output is:
INSERT followed by the
UPDATE? This breaks when there is a null constraint on the join table.