conditions fix

rest_gorm/request_list.go

@@ -49,6 +49,9 @@ func (s *List) Result(pg *gorm.DB, fields rest.FieldNamesList, res any) (count i
 			if cond.Operator != "" && cond.Operator != rest.OperatorNot {
 				err = rest.ErrorFiled(cond.Field, "Expected empty operator or not")
 			}
+			if cond.Operator == rest.OperatorExists {
+				cond.Operator = rest.OperatorEmpty
+			}
 			q := fmt.Sprintf("%s is %s null", CamelToSnake(cond.Field), cond.Operator)
 			if i == 0 || cond.Logic == rest.LogicAND {
 				pg = pg.Where(q)