Fix != queries returning null fields for elasticsearch

Materials-Consortia · May 7, 2021 · d810c1a · d810c1a
1 parent 75beeee
commit d810c1a
Showing 1 changed file with 6 additions and 1 deletion.
diff --git a/optimade/filtertransformers/elasticsearch.py b/optimade/filtertransformers/elasticsearch.py
@@ -109,8 +109,13 @@ def _query_op(self, quantity, op, value, nested=None):
             return Q(query_type, **{field: value})
 
         if op == "!=":
-            return ~Q(  # pylint: disable=invalid-unary-operand-type
+            # != queries must also include an existence check
+            # Note that for MongoDB, `$exists` will include null-valued fields,
+            # where as in ES `exists` excludes them.
+            return ~Q(
                 query_type, **{field: value}
+            ) & Q(  # pylint: disable=invalid-unary-operand-type
+                "exists", field=field
             )
 
     def _has_query_op(self, quantities, op, predicate_zip_list):