Fixed #28702 -- Made query lookups for CIText fields use citext.

1 files changed, 4 insertions, 3 deletions

diff --git a/django/db/backends/postgresql/schema.py b/django/db/backends/postgresql/schema.py
index 20cea3f249..18388cc523 100644
--- a/django/db/backends/postgresql/schema.py
+++ b/django/db/backends/postgresql/schema.py
@@ -107,11 +107,12 @@ class DatabaseSchemaEditor(BaseDatabaseSchemaEditor):
 
     def _alter_field(self, model, old_field, new_field, old_type, new_type,
                      old_db_params, new_db_params, strict=False):
-        # Drop indexes on varchar/text columns that are changing to a different
-        # type.
+        # Drop indexes on varchar/text/citext columns that are changing to a
+        # different type.
         if (old_field.db_index or old_field.unique) and (
             (old_type.startswith('varchar') and not new_type.startswith('varchar')) or
-            (old_type.startswith('text') and not new_type.startswith('text'))
+            (old_type.startswith('text') and not new_type.startswith('text')) or
+            (old_type.startswith('citext') and not new_type.startswith('citext'))
         ):
             index_name = self._create_index_name(model._meta.db_table, [old_field.column], suffix='_like')
             self.execute(self._delete_constraint_sql(self.sql_delete_index, model, index_name))