Admin Interface generates malformed SQL with many-to-many fields

[alexander.hungenberg@…]

I am using latest Revision (7438)

class Teacher(models.Model):
    short = models.CharField(max_length=20)
    account = models.ForeignKey(User, unique=True, blank=True, null=True)
    
    def __unicode__(self):
        if self.account:
            return self.account.last_name + ", " + self.account.first_name
        else:
            return self.short
    
    class Admin:
        list_display = ('account', 'short')

class Class(models.Model):
    name = models.CharField(max_length=3, unique=True)
    teacher = models.ManyToManyField(Teacher, unique=True, blank=True, null=True)
    room = models.ForeignKey(Room, blank=True, null=True)
    enabled_functions = models.ManyToManyField(Function, blank=True, null=True)
    
    def __unicode__(self):
        return self.name
    
    class Admin:
        list_display = ('name', 'room')

When I try to add a Teacher to a Class via the admin-interface, it throws the following Exception:

(1064, "You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near '))' at line 1")

the executed query taken from MySQL Log is

SELECT m2db_class.id,m2db_class.name,m2db_class.room_id FROM m2db_class LEFT OUTER JOIN m2db_class_teacher AS m2m_m2db_class__teacher ON m2db_class.id = m2m_m2db_class__teacher.class_id WHERE (m2m_m2db_class__teacher.teacher_id = ("'1'",))

Other many-to-many fields work normal...

If you need further Infos, contect me by mail or as defreng in #django. I could even give you some access to the admin page

[anonymous]

the trigger seems to be the unique=True option in the Class model

[Jason Davies]

I can confirm this bug, it seems to occur when unique=True is used in a ManyToManyField.

[Charlie La Mothe]

Adds model validation to check that unique = True is not set in ManyToManyFields. Also contains invalid_model tests to test for the validation.

[Malcolm Tredinnick]

(In [8488]) Fixed #7042 -- The management validation command nows alerts users to the
presence (and incorrectness) of unique=True on ManyToManyFields. This has never
worked and generates invalid SQL. Now it's raised as an explicit error during
validation. Thanks to clamothe for the patch.

Still needs a docs change to make this clear, but that goes to the docs
refactor branch.

[Jacob]

Milestone 1.0 deleted