Fix m2m joins.

Author: WaVEV

django_mongodb_backend/query.py

@@ -188,9 +188,9 @@ def _get_reroot_replacements(expression):
             self.parent_alias, lhs, compiler.collection_name, rhs
         )
         if (
-            isinstance(lhs, ForeignKey)
-            and isinstance(lhs_prepared, Col)
-            and isinstance(rhs_prepared, Col)
+            (isinstance(lhs, ForeignKey) or isinstance(rhs, ForeignKey))
+            and lhs_prepared.is_simple_column
+            and rhs_prepared.is_simple_column
         ):
             local_field = lhs_prepared.as_mql(compiler, connection)
             foreign_field = rhs_prepared.as_mql(compiler, connection)

tests/queries_/test_mql.py

@@ -129,24 +129,10 @@ def test_filter_on_reverse_foreignkey_relation(self):
                 {
                     "$lookup": {
                         "from": "queries__orderitem",
-                        "let": {"parent__field__0": "$_id"},
-                        "pipeline": [
-                            {
-                                "$match": {
-                                    "$and": [
-                                        {
-                                            "$expr": {
-                                                "$and": [
-                                                    {"$eq": ["$$parent__field__0", "$order_id"]}
-                                                ]
-                                            }
-                                        },
-                                        {"status": ObjectId("6891ff7822e475eddc20f159")},
-                                    ]
-                                }
-                            }
-                        ],
+                        "localField": "_id",
+                        "foreignField": "order_id",
                         "as": "queries__orderitem",
+                        "pipeline": [{"$match": {"status": ObjectId("6891ff7822e475eddc20f159")}}],
                     }
                 },
                 {"$unwind": "$queries__orderitem"},
@@ -172,24 +158,10 @@ def test_filter_on_local_and_nested_join_fields(self):
                 {
                     "$lookup": {
                         "from": "queries__orderitem",
-                        "pipeline": [
-                            {
-                                "$match": {
-                                    "$and": [
-                                        {
-                                            "$expr": {
-                                                "$and": [
-                                                    {"$eq": ["$$parent__field__0", "$order_id"]}
-                                                ]
-                                            }
-                                        },
-                                        {"status": ObjectId("6891ff7822e475eddc20f159")},
-                                    ]
-                                }
-                            }
-                        ],
+                        "localField": "_id",
+                        "foreignField": "order_id",
+                        "pipeline": [{"$match": {"status": ObjectId("6891ff7822e475eddc20f159")}}],
                         "as": "queries__orderitem",
-                        "let": {"parent__field__0": "$_id"},
                     }
                 },
                 {"$unwind": "$queries__orderitem"},
@@ -281,25 +253,14 @@ def test_push_equality_between_parent_and_child_fields(self):
             [
                 {
                     "$lookup": {
-                        "as": "queries__orderitem",
                         "from": "queries__orderitem",
-                        "let": {"parent__field__0": "$_id", "parent__field__1": "$_id"},
+                        "let": {"parent__field__0": "$_id"},
                         "pipeline": [
-                            {
-                                "$match": {
-                                    "$and": [
-                                        {
-                                            "$expr": {
-                                                "$and": [
-                                                    {"$eq": ["$$parent__field__0", "$order_id"]}
-                                                ]
-                                            }
-                                        },
-                                        {"$expr": {"$eq": ["$status", "$$parent__field__1"]}},
-                                    ]
-                                }
-                            }
+                            {"$match": {"$expr": {"$eq": ["$status", "$$parent__field__0"]}}}
                         ],
+                        "as": "queries__orderitem",
+                        "localField": "_id",
+                        "foreignField": "order_id",
                     }
                 },
                 {"$unwind": "$queries__orderitem"},
@@ -321,17 +282,10 @@ def test_simple_related_filter_is_pushed(self):
                 {
                     "$lookup": {
                         "from": "queries__library_readers",
-                        "pipeline": [
-                            {
-                                "$match": {
-                                    "$expr": {
-                                        "$and": [{"$eq": ["$$parent__field__0", "$library_id"]}]
-                                    }
-                                }
-                            }
-                        ],
+                        "pipeline": [],
                         "as": "queries__library_readers",
-                        "let": {"parent__field__0": "$_id"},
+                        "localField": "_id",
+                        "foreignField": "library_id",
                     }
                 },
                 {"$unwind": "$queries__library_readers"},
@@ -440,17 +394,10 @@ def test_filter_on_local_and_related_fields(self):
                 {
                     "$lookup": {
                         "from": "queries__library_readers",
-                        "pipeline": [
-                            {
-                                "$match": {
-                                    "$expr": {
-                                        "$and": [{"$eq": ["$$parent__field__0", "$library_id"]}]
-                                    }
-                                }
-                            }
-                        ],
+                        "localField": "_id",
+                        "foreignField": "library_id",
+                        "pipeline": [],
                         "as": "queries__library_readers",
-                        "let": {"parent__field__0": "$_id"},
                     }
                 },
                 {"$unwind": "$queries__library_readers"},
@@ -482,17 +429,10 @@ def test_annotate_foreign_field(self):
                 {
                     "$lookup": {
                         "from": "queries__library_readers",
-                        "pipeline": [
-                            {
-                                "$match": {
-                                    "$expr": {
-                                        "$and": [{"$eq": ["$$parent__field__0", "$library_id"]}]
-                                    }
-                                }
-                            }
-                        ],
+                        "localField": "_id",
+                        "foreignField": "library_id",
+                        "pipeline": [],
                         "as": "queries__library_readers",
-                        "let": {"parent__field__0": "$_id"},
                     }
                 },
                 {
@@ -564,17 +504,10 @@ def test_or_with_mixed_pushable_and_non_pushable_fields(self):
                 {
                     "$lookup": {
                         "from": "queries__library_readers",
-                        "pipeline": [
-                            {
-                                "$match": {
-                                    "$expr": {
-                                        "$and": [{"$eq": ["$$parent__field__0", "$library_id"]}]
-                                    }
-                                }
-                            }
-                        ],
+                        "localField": "_id",
+                        "foreignField": "library_id",
+                        "pipeline": [],
                         "as": "queries__library_readers",
-                        "let": {"parent__field__0": "$_id"},
                     }
                 },
                 {