implement SchemaEditor.alter_index_together()

Author: timgraham

django_mongodb/features.py

@@ -84,9 +84,6 @@ class DatabaseFeatures(BaseDatabaseFeatures):
  # AlterField (unique)
  "schema.tests.SchemaTests.test_unique",
  "schema.tests.SchemaTests.test_unique_and_reverse_m2m",
- # alter_index_together
- "migrations.test_operations.OperationTests.test_alter_index_together",
- "schema.tests.SchemaTests.test_index_together",
  # alter_unique_together
  "migrations.test_operations.OperationTests.test_alter_unique_together",
  "schema.tests.SchemaTests.test_unique_together",

django_mongodb/schema.py

@@ -100,7 +100,14 @@ def remove_field(self, model, field):
  self._remove_field_index(model, field)
 
  def alter_index_together(self, model, old_index_together, new_index_together):
- pass
+ olds = {tuple(fields) for fields in old_index_together}
+ news = {tuple(fields) for fields in new_index_together}
+ # Deleted indexes
+ for field_names in olds.difference(news):
+ self._remove_composed_index(model, field_names, {"index": True, "unique": False})
+ # Created indexes
+ for field_names in news.difference(olds):
+ self._add_composed_index(model, field_names)
 
  def alter_unique_together(self, model, old_unique_together, new_unique_together):
  pass
@@ -138,6 +145,30 @@ def remove_index(self, model, index):
  return
  self.get_collection(model._meta.db_table).drop_index(index.name)
 
+ def _remove_composed_index(self, model, field_names, constraint_kwargs):
+ """
+ Remove the index on the given list of field_names created by
+ index/unique_together, depending on constraint_kwargs.
+ """
+ meta_constraint_names = {constraint.name for constraint in model._meta.constraints}
+ meta_index_names = {constraint.name for constraint in model._meta.indexes}
+ columns = [model._meta.get_field(field).column for field in field_names]
+ constraint_names = self._constraint_names(
+ model,
+ columns,
+ exclude=meta_constraint_names | meta_index_names,
+ **constraint_kwargs,
+ )
+ if len(constraint_names) != 1:
+ num_found = len(constraint_names)
+ columns_str = ", ".join(columns)
+ raise ValueError(
+ f"Found wrong number ({num_found}) of constraints for "
+ f"{model._meta.db_table}({columns_str})."
+ )
+ collection = self.get_collection(model._meta.db_table)
+ collection.drop_index(constraint_names[0])
+
  def _remove_field_index(self, model, field):
  """Remove a field's db_index=True index."""
  collection = self.get_collection(model._meta.db_table)