Well I make the assignments in the table 'edit_assignments' manually, so now it's allright. I think that it's good how it is (the assignment of director to track, and papers), but a easy way to assignment current track's papers to the new directors of a track could be implemented, some method who calls the INSERT INTO edit_assignments (paper_id, director_id) SELECT [...], you know what I mean?
I don't know if I said it right but, the point it's solved

Thanks for help

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