On Wed, Oct 27, 2010 at 8:07 AM, Dan <dannyetdi...@gmail.com> wrote: > Structure: > > Projects > - project_id > - project_name > > Contacts > - contact_id > - contact_name > > Contacts_Projects > - project_id > - contact_id > > When reading the Cookbook, in a HABTM setting, I should add an ID > field to the Contacts_Projects table.
That's not a requirement. But, if you find that you need to store extra information in the join table, it's recommended that you then add a primary key. > Wouldn't this field enable the > possibility of having duplicates? UNIQUE(project_id, contact_id); This creates an index. That's why a PK isn't absolutely necessary. > Or does the ID field only act as auto number, but the key is still > composed of project_id/contact_id? Sort of. The id column becomes the PK and you'd then have two indexes on the table. If you do add a PK, you should keep the unique index as that's what Cake will be using. However, Cake doesn't ever use multi-column PKs.. Check out the new CakePHP Questions site http://cakeqs.org and help others with their CakePHP related questions. You received this message because you are subscribed to the Google Groups "CakePHP" group. To post to this group, send email to cake-php@googlegroups.com To unsubscribe from this group, send email to cake-php+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/cake-php?hl=en
