Ticket #11702: new_patch.patch

django/core/management/validation.py

@@ -79 +79 @@
                 # so skip the next section
                 if isinstance(f.rel.to, (str, unicode)):
                     continue
+                # Let's make sure we have unique=True if to_field is set in a ForeignKey#
+                if f.rel.field_name:
+                    to_field = f.rel.field_name or (r.rel.to._meta.pk and f.rel.to._meta.pk.name)
+                    if to_field:
+                        try:
+                            assert f.rel.to._meta.get_field(to_field).unique, \
+                                   "Field %s under model %s must have a unique=True constraint." % (to_field, f.rel.to.__name__)
+                        except:
+                            e.add(opts, "Field '%s' under model '%s' must have a unique=True constraint." % (to_field, f.rel.to.__name__))
 
                 rel_opts = f.rel.to._meta
                 rel_name = RelatedObject(f.rel.to, cls, f).get_accessor_name()

tests/modeltests/invalid_models/models.py

@@ -182 +182 @@
     """ Model to test for unique ManyToManyFields, which are invalid. """
     unique_people = models.ManyToManyField( Person, unique=True )
 
+class Author(models.Model): 
+    code = models.CharField(max_length=10, db_index=True)
+    first_name = models.CharField(max_length=30) 
+    last_name = models.CharField(max_length=40) 
 
+class Book(models.Model):
+    """This model should fail"""
+    title = models.CharField(max_length=100) 
+    author = models.ForeignKey(Author, to_field='code')
+
 model_errors = """invalid_models.fielderrors: "charfield": CharFields require a "max_length" attribute.
 invalid_models.fielderrors: "decimalfield": DecimalFields require a "decimal_places" attribute.
 invalid_models.fielderrors: "decimalfield": DecimalFields require a "max_digits" attribute.
@@ -279 +288 @@
 invalid_models.abstractrelationmodel: 'fk1' has a relation with model AbstractModel, which has either not been installed or is abstract.
 invalid_models.abstractrelationmodel: 'fk2' has an m2m relation with model AbstractModel, which has either not been installed or is abstract.
 invalid_models.uniquem2m: ManyToManyFields cannot be unique.  Remove the unique argument on 'unique_people'.
+invalid_models.book: Field 'code' under model 'Author' must have a unique=True constraint.
 """