Adding Foreign Keys to Composite Primary Key, referencing 2 tables I have a composite primary key
PRIMARY KEY (alpha, beta)
I want to add foreign keys to primary keys alpha and beta
I tried:
-- ADD FOREIGN KEY (alpha) REFERENCES green(alpha);
-- ADD FOREIGN KEY (beta) REFERENCES blue(beta);

This didn't work. I then tried:
ADD FOREIGN KEY (alpha, beta) REFERENCES green(alpha), blue(beta);

And this didn't work either. I can't find any examples online of adding different foreign keys to the composite primary key. Any tips would be welcome.
I had UNSIGNED on the referencing table but not on the referenced. That caused the issue it seems.