Many-to-many relations are dropped when updating a foreign entity in symfony

Question

I'm working with Symfony 1.2 (can't update, it's not up to me) with Propel as ORM. I'm having a bizarre problem with my many-to-many relations.

Let's say you have two tables A and B, and a many-to-many relation A_has_B. Let's say I have an a entity in A, a b entity in B, and a relation in A_has_B which PK is (a_id, b_id). Now, if I update b entity (not its id, but another field which is not its PK) using symfony admin generated modules, then (a_id, b_id) is dropped from the database.

This only happens using Symfony backend. It DOESN'T happen using phpmyadmin, where I can update a and b without loosing (a_id, b_id) relation.

All tables are MySQL/InnoDB. Columns A_id and B_id in A_has_B are foreign keys pointing to A and B id's. I have ON DELETE CASCADE and ON UPDATE CASCADE in both columns.

Thank you very much for your help.

UPDATE: Here is the yml schema, for three tables Team and Participants and its relation

propel:
  _attributes:
    package: lib.model
    defaultIdMethod: native
  team:
    _attributes: { phpName: Team }
    id: { type: INTEGER, size: '11', primaryKey: true, autoIncrement: true, required: true }
    name: { type: VARCHAR, size: '255', required: true }
    description: { type: LONGVARCHAR, required: false }
  participant:
    _attributes: { phpName: Participant }
    id: { type: INTEGER, size: '11', primaryKey: true, autoIncrement: true, required: true }
    name: { type: VARCHAR, size: '255', required: true }
  team_has_participant:
    _attributes: { phpName: TeamHasParticipant }
    team_id: { type: INTEGER, size: '11', primaryKey: true, required: true, foreignTable: team, foreignReference: id, onDelete: CASCADE, onUpdate: CASCADE }
    participant_id: { type: INTEGER, size: '11', primaryKey: true, required: true, foreignTable: participant, foreignReference: id, onDelete: CASCADE, onUpdate: CASCADE }
    _indexes: { participant_id: [participant_id] }

Say I update description field in a team entity, then I'm loosing all the team_has_participant relations that had that foreign team entity.

i don't see the problem. If you update the `b` entity's id, the link table entry is no longer valid. That is how its suposed to work. — Andreu Ramos, Dec 30 '11 at 14:07
But I'm not updating `b` entitity's id, I'm updating another field which is not its PK, so the entity is the same and the link table shouldn't be dropped (as it's happening using phpmyadmin instead of symfony backend) — Waiting for Dev..., Dec 30 '11 at 14:15
i think its an issue of phpMyAdmin. If you tag the question with `php` and `phpMyAdmin` probably expert people could help you. Good luck — Andreu Ramos, Dec 30 '11 at 16:57
It can't be. phpmyadmin is doing well. It's a problem with symfony, php or mysql. Thank you @Andreu Heineken — Waiting for Dev..., Dec 30 '11 at 17:11

Waiting for Dev... · Accepted Answer · 2012-01-10T11:35:06.943

Ok, I realized what the problem was. Of course, something silly.

In my relations, say A_has_B I was hidding the a_has_b_list field in B generator.yml to only allow modifications from A form. But it's a mistake, because just hidding the field in generator.yml doesn't unset it, just hidde it and it is posted with a blank value (so it overrides the database). It's necessary to unset the widget in B form configure() method:

unset($this->widgetSchema['a_has_b_list'];

This way, nothing is posted and database is not overriden.

Many-to-many relations are dropped when updating a foreign entity in symfony

1 Answers1