Add unique_together altering operation

7 files changed, 84 insertions, 17 deletions

diff --git a/django/db/migrations/operations/__init__.py b/django/db/migrations/operations/__init__.py
index 925b05fff3..afa5c85cdc 100644
--- a/django/db/migrations/operations/__init__.py
+++ b/django/db/migrations/operations/__init__.py
@@ -1,2 +1,2 @@
-from .models import CreateModel, DeleteModel, AlterModelTable
+from .models import CreateModel, DeleteModel, AlterModelTable, AlterUniqueTogether
 from .fields import AddField, RemoveField, AlterField, RenameField
diff --git a/django/db/migrations/operations/fields.py b/django/db/migrations/operations/fields.py
index cc4f4a43df..37e0c063e1 100644
--- a/django/db/migrations/operations/fields.py
+++ b/django/db/migrations/operations/fields.py
@@ -7,7 +7,7 @@ class AddField(Operation):
     """
 
     def __init__(self, model_name, name, field):
-        self.model_name = model_name
+        self.model_name = model_name.lower()
         self.name = name
         self.field = field
 
@@ -33,7 +33,7 @@ class RemoveField(Operation):
     """
 
     def __init__(self, model_name, name):
-        self.model_name = model_name
+        self.model_name = model_name.lower()
         self.name = name
 
     def state_forwards(self, app_label, state):
@@ -62,7 +62,7 @@ class AlterField(Operation):
     """
 
     def __init__(self, model_name, name, field):
-        self.model_name = model_name
+        self.model_name = model_name.lower()
         self.name = name
         self.field = field
 
@@ -93,7 +93,7 @@ class RenameField(Operation):
     """
 
     def __init__(self, model_name, old_name, new_name):
-        self.model_name = model_name
+        self.model_name = model_name.lower()
         self.old_name = old_name
         self.new_name = new_name
 
diff --git a/django/db/migrations/operations/models.py b/django/db/migrations/operations/models.py
index c73ff179d4..7279a163f0 100644
--- a/django/db/migrations/operations/models.py
+++ b/django/db/migrations/operations/models.py
@@ -9,7 +9,7 @@ class CreateModel(Operation):
     """
 
     def __init__(self, name, fields, options=None, bases=None):
-        self.name = name
+        self.name = name.lower()
         self.fields = fields
         self.options = options or {}
         self.bases = bases or (models.Model,)
@@ -35,7 +35,7 @@ class DeleteModel(Operation):
     """
 
     def __init__(self, name):
-        self.name = name
+        self.name = name.lower()
 
     def state_forwards(self, app_label, state):
         del state.models[app_label, self.name.lower()]
@@ -58,7 +58,7 @@ class AlterModelTable(Operation):
     """
 
     def __init__(self, name, table):
-        self.name = name
+        self.name = name.lower()
         self.table = table
 
     def state_forwards(self, app_label, state):
@@ -78,3 +78,33 @@ class AlterModelTable(Operation):
 
     def describe(self):
         return "Rename table for %s to %s" % (self.name, self.table)
+
+
+class AlterUniqueTogether(Operation):
+    """
+    Changes the value of unique_together to the target one.
+    Input value of unique_together must be a set of tuples.
+    """
+
+    def __init__(self, name, unique_together):
+        self.name = name.lower()
+        self.unique_together = set(tuple(cons) for cons in unique_together)
+
+    def state_forwards(self, app_label, state):
+        model_state = state.models[app_label, self.name.lower()]
+        model_state.options["unique_together"] = self.unique_together
+
+    def database_forwards(self, app_label, schema_editor, from_state, to_state):
+        old_app_cache = from_state.render()
+        new_app_cache = to_state.render()
+        schema_editor.alter_unique_together(
+            new_app_cache.get_model(app_label, self.name),
+            getattr(old_app_cache.get_model(app_label, self.name)._meta, "unique_together", set()),
+            getattr(new_app_cache.get_model(app_label, self.name)._meta, "unique_together", set()),
+        )
+
+    def database_backwards(self, app_label, schema_editor, from_state, to_state):
+        return self.database_forwards(app_label, schema_editor, from_state, to_state)
+
+    def describe(self):
+        return "Alter unique_together for %s (%s constraints)" % (self.name, len(self.unique_together))
diff --git a/django/db/migrations/state.py b/django/db/migrations/state.py
index 4ecdb18896..8f0078d731 100644
--- a/django/db/migrations/state.py
+++ b/django/db/migrations/state.py
@@ -80,8 +80,11 @@ class ModelState(object):
             # Ignore some special options
             if name in ["app_cache", "app_label"]:
                 continue
-            if name in model._meta.original_attrs:
-                options[name] = model._meta.original_attrs[name]
+            elif name in model._meta.original_attrs:
+                if name == "unique_together":
+                    options[name] = set(model._meta.original_attrs["unique_together"])
+                else:
+                    options[name] = model._meta.original_attrs[name]
         # Make our record
         bases = tuple(model for model in model.__bases__ if (not hasattr(model, "_meta") or not model._meta.abstract))
         if not bases:
@@ -116,6 +119,8 @@ class ModelState(object):
         # First, make a Meta object
         meta_contents = {'app_label': self.app_label, "app_cache": app_cache}
         meta_contents.update(self.options)
+        if "unique_together" in meta_contents:
+            meta_contents["unique_together"] = list(meta_contents["unique_together"])
         meta = type("Meta", tuple(), meta_contents)
         # Then, work out our bases
         # TODO: Use the actual bases
diff --git a/tests/migrations/test_autodetector.py b/tests/migrations/test_autodetector.py
index 540e84e8df..659b45dbd2 100644
--- a/tests/migrations/test_autodetector.py
+++ b/tests/migrations/test_autodetector.py
@@ -83,7 +83,7 @@ class AutodetectorTests(TestCase):
         # Right action?
         action = migration.operations[0]
         self.assertEqual(action.__class__.__name__, "CreateModel")
-        self.assertEqual(action.name, "Author")
+        self.assertEqual(action.name, "author")
 
     def test_old_model(self):
         "Tests deletion of old models"
@@ -100,7 +100,7 @@ class AutodetectorTests(TestCase):
         # Right action?
         action = migration.operations[0]
         self.assertEqual(action.__class__.__name__, "DeleteModel")
-        self.assertEqual(action.name, "Author")
+        self.assertEqual(action.name, "author")
 
     def test_add_field(self):
         "Tests autodetection of new fields"
diff --git a/tests/migrations/test_operations.py b/tests/migrations/test_operations.py
index 2e72e11954..b2912de53c 100644
--- a/tests/migrations/test_operations.py
+++ b/tests/migrations/test_operations.py
@@ -1,5 +1,6 @@
 from django.test import TestCase
 from django.db import connection, models, migrations
+from django.db.utils import IntegrityError
 from django.db.migrations.state import ProjectState
 
 
@@ -38,6 +39,7 @@ class OperationTests(TestCase):
             [
                 ("id", models.AutoField(primary_key=True)),
                 ("pink", models.BooleanField(default=True)),
+                ("weight", models.FloatField()),
             ],
         )
         project_state = ProjectState()
@@ -50,7 +52,7 @@ class OperationTests(TestCase):
     def test_create_model(self):
         """
         Tests the CreateModel operation.
-        Most other tests use this as part of setup, so check failures here first.
+        Most other tests use this operation as part of setup, so check failures here first.
         """
         operation = migrations.CreateModel(
             "Pony",
@@ -63,7 +65,7 @@ class OperationTests(TestCase):
         project_state = ProjectState()
         new_state = project_state.clone()
         operation.state_forwards("test_crmo", new_state)
-        self.assertEqual(new_state.models["test_crmo", "pony"].name, "Pony")
+        self.assertEqual(new_state.models["test_crmo", "pony"].name, "pony")
         self.assertEqual(len(new_state.models["test_crmo", "pony"].fields), 2)
         # Test the database alteration
         self.assertTableNotExists("test_crmo_pony")
@@ -110,7 +112,7 @@ class OperationTests(TestCase):
         operation = migrations.AddField("Pony", "height", models.FloatField(null=True))
         new_state = project_state.clone()
         operation.state_forwards("test_adfl", new_state)
-        self.assertEqual(len(new_state.models["test_adfl", "pony"].fields), 3)
+        self.assertEqual(len(new_state.models["test_adfl", "pony"].fields), 4)
         # Test the database alteration
         self.assertColumnNotExists("test_adfl_pony", "height")
         with connection.schema_editor() as editor:
@@ -130,7 +132,7 @@ class OperationTests(TestCase):
         operation = migrations.RemoveField("Pony", "pink")
         new_state = project_state.clone()
         operation.state_forwards("test_rmfl", new_state)
-        self.assertEqual(len(new_state.models["test_rmfl", "pony"].fields), 1)
+        self.assertEqual(len(new_state.models["test_rmfl", "pony"].fields), 2)
         # Test the database alteration
         self.assertColumnExists("test_rmfl_pony", "pink")
         with connection.schema_editor() as editor:
@@ -208,3 +210,33 @@ class OperationTests(TestCase):
             operation.database_backwards("test_rnfl", editor, new_state, project_state)
         self.assertColumnExists("test_rnfl_pony", "pink")
         self.assertColumnNotExists("test_rnfl_pony", "blue")
+
+    def test_alter_unique_together(self):
+        """
+        Tests the AlterUniqueTogether operation.
+        """
+        project_state = self.set_up_test_model("test_alunto")
+        # Test the state alteration
+        operation = migrations.AlterUniqueTogether("Pony", [("pink", "weight")])
+        new_state = project_state.clone()
+        operation.state_forwards("test_alunto", new_state)
+        self.assertEqual(len(project_state.models["test_alunto", "pony"].options.get("unique_together", set())), 0)
+        self.assertEqual(len(new_state.models["test_alunto", "pony"].options.get("unique_together", set())), 1)
+        # Make sure we can insert duplicate rows
+        cursor = connection.cursor()
+        cursor.execute("INSERT INTO test_alunto_pony (id, pink, weight) VALUES (1, 1, 1)")
+        cursor.execute("INSERT INTO test_alunto_pony (id, pink, weight) VALUES (2, 1, 1)")
+        cursor.execute("DELETE FROM test_alunto_pony")
+        # Test the database alteration
+        with connection.schema_editor() as editor:
+            operation.database_forwards("test_alunto", editor, project_state, new_state)
+        cursor.execute("INSERT INTO test_alunto_pony (id, pink, weight) VALUES (1, 1, 1)")
+        with self.assertRaises(IntegrityError):
+            cursor.execute("INSERT INTO test_alunto_pony (id, pink, weight) VALUES (2, 1, 1)")
+        cursor.execute("DELETE FROM test_alunto_pony")
+        # And test reversal
+        with connection.schema_editor() as editor:
+            operation.database_backwards("test_alunto", editor, new_state, project_state)
+        cursor.execute("INSERT INTO test_alunto_pony (id, pink, weight) VALUES (1, 1, 1)")
+        cursor.execute("INSERT INTO test_alunto_pony (id, pink, weight) VALUES (2, 1, 1)")
+        cursor.execute("DELETE FROM test_alunto_pony")
diff --git a/tests/migrations/test_state.py b/tests/migrations/test_state.py
index c6930873ef..e5b3fbfa08 100644
--- a/tests/migrations/test_state.py
+++ b/tests/migrations/test_state.py
@@ -44,7 +44,7 @@ class StateTests(TestCase):
         self.assertEqual(author_state.fields[1][1].max_length, 255)
         self.assertEqual(author_state.fields[2][1].null, False)
         self.assertEqual(author_state.fields[3][1].null, True)
-        self.assertEqual(author_state.options, {"unique_together": ["name", "bio"]})
+        self.assertEqual(author_state.options, {"unique_together": set(("name", "bio"))})
         self.assertEqual(author_state.bases, (models.Model, ))
         
         self.assertEqual(book_state.app_label, "migrations")