Add having.

Author: WaVEV

django_mongodb/compiler.py

@@ -21,9 +21,11 @@ class SQLCompiler(compiler.SQLCompiler):
     def pre_sql_setup(self, with_col_aliases=False):
         pre_setup = super().pre_sql_setup(with_col_aliases=with_col_aliases)
         self.annotations = {}
+        # mongo_having = self.having.copy() if self.having else None
         group = {}
         group_expressions = set()
         aggregation_idx = 1
+        all_replacements = {}
         for target, expr in self.query.annotation_select.items():
             if not expr.contains_aggregate:
                 result_expr = expr
@@ -41,7 +43,7 @@ def pre_sql_setup(self, with_col_aliases=False):
                     column_target.set_attributes_from_name(alias)
                     replacements[sub_expr] = Col(self.collection_name, column_target)
                 result_expr = expr.replace_expressions(replacements)
-
+                all_replacements.update(replacements)
             self.annotations[target] = result_expr
         if group:
             order_by = self.get_order_by()
@@ -61,7 +63,9 @@ def pre_sql_setup(self, with_col_aliases=False):
                 if not group_expressions
                 else {
                     col.target.column: col.as_mql(self, self.connection)
+                    # expression aren't needed in the group by clouse ()
                     for col in group_expressions
+                    if isinstance(col, Col)
                 }
             )
             group["_id"] = ids
@@ -71,7 +75,17 @@ def pre_sql_setup(self, with_col_aliases=False):
                     {"$addFields": {key: f"$_id.{value[1:]}" for key, value in ids.items()}}
                 )
                 if "_id" not in ids:
-                    pipeline.append({"$unSet": "$_id"})
+                    pipeline.append({"$unset": "_id"})
+            if self.having:
+                pipeline.append(
+                    {
+                        "$match": {
+                            "$expr": self.having.replace_expressions(all_replacements).as_mql(
+                                self, self.connection
+                            )
+                        }
+                    }
+                )
 
             self._group_pipeline = pipeline
         else:
@@ -206,7 +220,9 @@ def build_query(self, columns=None):
         query.lookup_pipeline = self.get_lookup_pipeline()
         query.project_fields = self.get_project_fields(columns)
         try:
-            query.mongo_query = {"$expr": self.query.where.as_mql(self, self.connection)}
+            query.mongo_query = (
+                {"$expr": self.where.as_mql(self, self.connection)} if self.where else None
+            )
         except FullResultSet:
             query.mongo_query = {}
         query.order_by(self._get_ordering())
@@ -431,7 +447,8 @@ def execute_update(self, update_spec, **kwargs):
 class SQLAggregateCompiler(SQLCompiler):
     def build_query(self, columns=None):
         query = self.query_class(self)
-        query.project_fields = self.get_project_fields(tuple(self.query.annotation_select.items()))
+        query.project_fields = self.get_project_fields(tuple(self.annotations.items()))
+        query.aggregation_stage = self.get_aggregation_pipeline()
 
         compiler = self.query.inner_query.get_compiler(
             self.using,
@@ -440,3 +457,6 @@ def build_query(self, columns=None):
         compiler.pre_sql_setup(with_col_aliases=False)
         query.sub_query = compiler.build_query()
         return query
+
+    def _make_result(self, result, columns=None):
+        return [result[k] for k in self.query.annotation_select]

django_mongodb/functions.py

@@ -121,10 +121,13 @@ def count(self, compiler, connection, **extra_context):  # noqa: ARG001
         source_expressions = copy.get_source_expressions()
         condition = When(self.filter, then=Value(1))
         copy.set_source_expressions([Case(condition)] + source_expressions[1:])
-        lhs_mql = process_lhs(copy, compiler, connection)
+        node = copy
     else:
-        lhs_mql = Value(1).as_mql(compiler, connection)
-    return {"$sum": lhs_mql}
+        node = self
+        # lhs_mql = process_lhs(self, compiler, connection)
+    lhs_mql = process_lhs(node, compiler, connection)
+    null_cond = {"$in": [{"$type": lhs_mql}, ["missing", "null"]]}
+    return {"$sum": {"$cond": {"if": null_cond, "then": 0, "else": 1}}}
 
 
 def extract(self, compiler, connection):