Add as_path paramter

Author: WaVEV

django_mongodb_backend/expressions/builtins.py

@@ -53,7 +53,7 @@ def case(self, compiler, connection):
     }
 
 
-def col(self, compiler, connection):  # noqa: ARG001
+def col(self, compiler, connection, as_path=False):  # noqa: ARG001
     # If the column is part of a subquery and belongs to one of the parent
     # queries, it will be stored for reference using $let in a $lookup stage.
     # If the query is built with `alias_cols=False`, treat the column as
@@ -71,7 +71,7 @@ def col(self, compiler, connection):  # noqa: ARG001
     # Add the column's collection's alias for columns in joined collections.
     has_alias = self.alias and self.alias != compiler.collection_name
     prefix = f"{self.alias}." if has_alias else ""
-    return f"${prefix}{self.target.column}"
+    return f"{prefix}{self.target.column}" if as_path else f"${prefix}{self.target.column}"
 
 
 def col_pairs(self, compiler, connection):

django_mongodb_backend/fields/embedded_model.py

@@ -184,12 +184,16 @@ def get_transform(self, name):
             f"{suggestion}"
         )
 
-    def as_mql(self, compiler, connection):
+    def as_mql(self, compiler, connection, as_path=False):
         previous = self
         key_transforms = []
         while isinstance(previous, KeyTransform):
             key_transforms.insert(0, previous.key_name)
             previous = previous.lhs
+        if as_path:
+            mql = previous.as_mql(compiler, connection, as_path=True)
+            mql_path = ".".join(key_transforms)
+            return f"{mql}.{mql_path}"
         mql = previous.as_mql(compiler, connection)
         for key in key_transforms:
             mql = {"$getField": {"input": mql, "field": key}}