add support for ordering by F and OrderBy

Author: timgraham

django_mongodb/compiler.py

@@ -1,8 +1,8 @@
-from django.core.exceptions import EmptyResultSet, FieldDoesNotExist, FullResultSet
+from django.core.exceptions import EmptyResultSet, FullResultSet
 from django.db import DatabaseError, IntegrityError, NotSupportedError
 from django.db.models import Count, Expression
 from django.db.models.aggregates import Aggregate
-from django.db.models.constants import LOOKUP_SEP
+from django.db.models.expressions import OrderBy
 from django.db.models.sql import compiler
 from django.db.models.sql.constants import GET_ITERATOR_CHUNK_SIZE, MULTI
 from django.utils.functional import cached_property
@@ -207,24 +207,23 @@ def _get_ordering(self):
         for order in ordering:
             if order == "?":
                 raise NotSupportedError("Randomized ordering isn't supported by MongoDB.")
-
-            ascending = not order.startswith("-")
+            if hasattr(order, "resolve_expression"):
+                orderby = order if isinstance(order, OrderBy) else order.asc()
+                orderby = orderby.resolve_expression(self.query, allow_joins=True, reuse=None)
+                ascending = not orderby.descending
+            else:
+                ascending = not order.startswith("-")
+                name = order.lstrip("+-")
+                if name == "pk":
+                    name = opts.pk.name
+                orderby, _ = self.find_ordering_name(order, self.query.get_meta())[0]
+            column = orderby.expression.as_mql(self, self.connection)
+            if isinstance(column, dict):
+                raise NotSupportedError("order_by() expression not supported.")
+            column = column.removeprefix("$")
+            # If the query is reversed, ascending and descending are inverted.
             if not self.query.standard_ordering:
                 ascending = not ascending
-
-            name = order.lstrip("+-")
-            if name == "pk":
-                name = opts.pk.name
-
-            if LOOKUP_SEP in order:
-                orderby, _ = self.find_ordering_name(order, self.query.get_meta())[0]
-                column = orderby.expression.as_mql(self, self.connection).removeprefix("$")
-            else:
-                try:
-                    column = opts.get_field(name).column
-                except FieldDoesNotExist:
-                    # `name` is an annotation in $project.
-                    column = name
             column_ordering.append((column, ascending))
         return column_ordering
 

django_mongodb/expressions.py

@@ -9,6 +9,7 @@
     Col,
     CombinedExpression,
     ExpressionWrapper,
+    F,
     NegatedExpression,
     Ref,
     Subquery,
@@ -61,6 +62,10 @@ def expression_wrapper(self, compiler, connection):
     return self.expression.as_mql(compiler, connection)
 
 
+def f(self, compiler, connection):  # noqa: ARG001
+    return f"${self.name}"
+
+
 def negated_expression(self, compiler, connection):
     return {"$not": expression_wrapper(self, compiler, connection)}
 
@@ -102,6 +107,7 @@ def register_expressions():
     Col.as_mql = col
     CombinedExpression.as_mql = combined_expression
     ExpressionWrapper.as_mql = expression_wrapper
+    F.as_mql = f
     NegatedExpression.as_mql = negated_expression
     Query.as_mql = query
     Ref.as_mql = ref

django_mongodb/features.py

@@ -32,40 +32,30 @@ class DatabaseFeatures(BaseDatabaseFeatures):
         "lookup.tests.LookupTests.test_exact_none_transform",
         # "Save with update_fields did not affect any rows."
         "basic.tests.SelectOnSaveTests.test_select_on_save_lying_update",
-        # Lookup in order_by() not supported:
-        # argument of type '<database function>' is not iterable
+        # Order by constant not supported:
+        # AttributeError: 'Field' object has no attribute 'model'
+        "ordering.tests.OrderingTests.test_order_by_constant_value",
+        "expressions.tests.NegatedExpressionTests.test_filter",
+        "expressions_case.tests.CaseExpressionTests.test_order_by_conditional_implicit",
+        # NotSupportedError: order_by() expression not supported.
         "db_functions.comparison.test_coalesce.CoalesceTests.test_ordering",
         "db_functions.tests.FunctionTests.test_nested_function_ordering",
         "db_functions.text.test_length.LengthTests.test_ordering",
         "db_functions.text.test_strindex.StrIndexTests.test_order_by",
-        "expressions.tests.BasicExpressionsTests.test_order_by_exists",
-        "expressions.tests.BasicExpressionsTests.test_order_by_multiline_sql",
         "expressions_case.tests.CaseExpressionTests.test_order_by_conditional_explicit",
         "lookup.tests.LookupQueryingTests.test_lookup_in_order_by",
-        "ordering.tests.OrderingTests.test_default_ordering",
-        "ordering.tests.OrderingTests.test_default_ordering_by_f_expression",
-        "ordering.tests.OrderingTests.test_default_ordering_does_not_affect_group_by",
-        "ordering.tests.OrderingTests.test_order_by_constant_value",
         "ordering.tests.OrderingTests.test_order_by_expr_query_reuse",
         "ordering.tests.OrderingTests.test_order_by_expression_ref",
-        "ordering.tests.OrderingTests.test_order_by_f_expression",
+        "ordering.tests.OrderingTests.test_ordering_select_related_collision",
+        "update.tests.AdvancedTests.test_update_ordered_by_inline_m2m_annotation",
+        "update.tests.AdvancedTests.test_update_ordered_by_m2m_annotation",
+        "update.tests.AdvancedTests.test_update_ordered_by_m2m_annotation_desc",
+        # Wrong results for ordering queries.
         "ordering.tests.OrderingTests.test_order_by_f_expression_duplicates",
-        "ordering.tests.OrderingTests.test_order_by_fk_attname",
         "ordering.tests.OrderingTests.test_order_by_nulls_first",
         "ordering.tests.OrderingTests.test_order_by_nulls_last",
-        "ordering.tests.OrderingTests.test_ordering_select_related_collision",
         "ordering.tests.OrderingTests.test_order_by_self_referential_fk",
-        "ordering.tests.OrderingTests.test_orders_nulls_first_on_filtered_subquery",
         "ordering.tests.OrderingTests.test_related_ordering_duplicate_table_reference",
-        "ordering.tests.OrderingTests.test_reverse_ordering_pure",
-        "ordering.tests.OrderingTests.test_reverse_meta_ordering_pure",
-        "ordering.tests.OrderingTests.test_reversed_ordering",
-        "update.tests.AdvancedTests.test_update_ordered_by_inline_m2m_annotation",
-        "update.tests.AdvancedTests.test_update_ordered_by_m2m_annotation",
-        "update.tests.AdvancedTests.test_update_ordered_by_m2m_annotation_desc",
-        # 'ManyToOneRel' object has no attribute 'column'
-        "m2m_through.tests.M2mThroughTests.test_order_by_relational_field_through_model",
-        "queries.tests.Queries4Tests.test_order_by_reverse_fk",
         # pymongo: ValueError: update cannot be empty
         "update.tests.SimpleTest.test_empty_update_with_inheritance",
         "update.tests.SimpleTest.test_nonempty_update_with_inheritance",
@@ -144,6 +134,8 @@ class DatabaseFeatures(BaseDatabaseFeatures):
         "queries.tests.Queries1Tests.test_tickets_2076_7256",
         # filter() on related model + update() doesn't work.
         "queries.tests.Queries5Tests.test_ticket9848",
+        # ???
+        "expressions.tests.BasicExpressionsTests.test_outerref",
     }
     # $bitAnd, #bitOr, and $bitXor are new in MongoDB 6.3.
     _django_test_expected_failures_bitwise = {
@@ -327,6 +319,7 @@ def django_test_expected_failures(self):
             "expressions.tests.BasicExpressionsTests.test_boolean_expression_in_Q",
             "expressions.tests.BasicExpressionsTests.test_case_in_filter_if_boolean_output_field",
             "expressions.tests.BasicExpressionsTests.test_exists_in_filter",
+            "expressions.tests.BasicExpressionsTests.test_order_by_exists",
             "expressions.tests.BasicExpressionsTests.test_subquery",
             "expressions.tests.ExistsTests.test_filter_by_empty_exists",
             "expressions.tests.ExistsTests.test_negated_empty_exists",
@@ -445,6 +438,7 @@ def django_test_expected_failures(self):
             "expressions.tests.FieldTransformTests.test_month_aggregation",
             "expressions_case.tests.CaseDocumentationExamples.test_conditional_aggregation_example",
             "model_fields.test_jsonfield.TestQuerying.test_ordering_grouping_by_count",
+            "ordering.tests.OrderingTests.test_default_ordering_does_not_affect_group_by",
             "queries.tests.Queries1Tests.test_ticket_20250",
             "queries.tests.ValuesQuerysetTests.test_named_values_list_expression_with_default_alias",
         },
@@ -478,6 +472,7 @@ def django_test_expected_failures(self):
         },
         "QuerySet.distinct() is not supported.": {
             "lookup.tests.LookupTests.test_lookup_collision_distinct",
+            "ordering.tests.OrderingTests.test_orders_nulls_first_on_filtered_subquery",
             "queries.tests.ExcludeTest17600.test_exclude_plain_distinct",
             "queries.tests.ExcludeTest17600.test_exclude_with_q_is_equal_to_plain_exclude",
             "queries.tests.ExcludeTest17600.test_exclude_with_q_object_distinct",
@@ -536,6 +531,7 @@ def django_test_expected_failures(self):
             "delete_regress.tests.DeleteLockingTest.test_concurrent_delete",
             "expressions.tests.BasicExpressionsTests.test_annotate_values_filter",
             "expressions.tests.BasicExpressionsTests.test_filtering_on_rawsql_that_is_boolean",
+            "expressions.tests.BasicExpressionsTests.test_order_by_multiline_sql",
             "model_fields.test_jsonfield.TestQuerying.test_key_sql_injection_escape",
             "model_fields.test_jsonfield.TestQuerying.test_key_transform_raw_expression",
             "model_fields.test_jsonfield.TestQuerying.test_nested_key_transform_raw_expression",