Parse.com嵌套查询包含doesNotMatchQuery

Question

我有User和GroupMember类与解析。

我在GroupMember类一个加入User指针列和想从User类获取所有用户，但不包括其存在于GroupMember类关系。

Answer 1

您必须进行两个查询，其中您从GroupMember的指针列中查询所有用户objectId，然后从User类的下一个查询中排除这些对象。

ParseQuery<ParseObject> a = ParseQuery.getQuery("GroupMember"); 
a.include("name of pointer column") 
a.findInBackground(new FindCallback...); // get list of objects id with for each loop 
//i.e. for (ParseObject o : list) String s = o.getParseObject("user_pointer_column").getObjectId(); 
//then add it to some list 

ParseQuery<ParseObject> b = ParseQuery.getQuery("User"); 
b.whereNotContainedIn("objectId", list_of_ids); 

或者其他方式：

ParseQuery<ParseObject> a = ParseQuery.getQuery("User"); 
ParseQuery<ParseObject> b = ParseQuery.getQuery("GroupMember"); 
b.whereDoesNotMatchQuery("user_pointer_column", a); 
b.findInBackground(new FindCallback...{...});