Parse.com 嵌套查询包含 doesNotMatchQuery

Question

我有 User 和 GroupMember 解析类。

我在GroupMember 类中添加了一个User 指针列，并希望从User 类中获取所有用户，但不包括GroupMember 类关系中存在的用户。

Answer 1

您必须进行两个查询，从GroupMembers 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...{...});