fix "AttributeError: pattern_ops" query crash

Author: timgraham

django_mongodb/base.py

@@ -72,6 +72,16 @@ class DatabaseWrapper(BaseDatabaseWrapper):
         "istartswith": "LIKE UPPER(%s)",
         "iendswith": "LIKE UPPER(%s)",
     }
+    # As with `operators`, these patterns are used to generate SQL before MQL.
+    pattern_esc = "%%"
+    pattern_ops = {
+        "contains": "LIKE '%%' || {} || '%%'",
+        "icontains": "LIKE '%%' || UPPER({}) || '%%'",
+        "startswith": "LIKE {} || '%%'",
+        "istartswith": "LIKE UPPER({}) || '%%'",
+        "endswith": "LIKE '%%' || {}",
+        "iendswith": "LIKE '%%' || UPPER({})",
+    }
     mongo_operators = {
         "exact": lambda a, b: {"$eq": [a, b]},
         "gt": lambda a, b: {"$gt": [a, b]},

django_mongodb/features.py

@@ -69,9 +69,6 @@ class DatabaseFeatures(BaseDatabaseFeatures):
         "expressions.tests.FTimeDeltaTests.test_invalid_operator",
         # 'Ref' object has no attribute 'as_mql'.
         "expressions.tests.BasicExpressionsTests.test_aggregate_subquery_annotation",
-        # AttributeError: pattern_ops
-        "expressions.tests.BasicExpressionsTests.test_annotation_with_nested_outerref",
-        "expressions.tests.BasicExpressionsTests.test_nested_outerref_with_function",
     }
     # $bitAnd, #bitOr, and $bitXor are new in MongoDB 6.3.
     _django_test_expected_failures_bitwise = {
@@ -290,9 +287,11 @@ def django_test_expected_failures(self):
             "annotations.tests.NonAggregateAnnotationTestCase.test_empty_queryset_annotation",
             "db_functions.datetime.test_extract_trunc.DateFunctionTests.test_extract_outerref",
             "db_functions.datetime.test_extract_trunc.DateFunctionTests.test_trunc_subquery_with_parameters",
+            "expressions.tests.BasicExpressionsTests.test_annotation_with_nested_outerref",
             "expressions.tests.BasicExpressionsTests.test_annotation_with_outerref",
             "expressions.tests.BasicExpressionsTests.test_annotations_within_subquery",
             "expressions.tests.BasicExpressionsTests.test_in_subquery",
+            "expressions.tests.BasicExpressionsTests.test_nested_outerref_with_function",
             "expressions.tests.BasicExpressionsTests.test_nested_subquery",
             "expressions.tests.BasicExpressionsTests.test_nested_subquery_join_outer_ref",
             "expressions.tests.BasicExpressionsTests.test_nested_subquery_outer_ref_2",