我正在尝试编写一个 PFQuery
来获取用户的 friend 作为 User 对象。下面显示的是我的用户表和 friend 查找表。当用户创建好友时,将在好友查找表中添加一个条目。
我的想法是构建一个查询,在 Lookup 表中查询 sendingUser
或 receivingUser
等于当前用户的任何行。
NSString * const kPULLookupSendingUserKey = @"sendingUser";
NSString * const kPULLookupReceivingUserKey = @"receivingUser";
....
PULUser *acct = [PULUser currentUser];
// query where sending user is current user
PFQuery *senderQuery = [PFQuery queryWithClassName:@"FriendLookup"];
[senderQuery whereKey:kPULLookupSendingUserKey equalTo:acct];
// query where receiving user is current user
PFQuery *recQuery = [PFQuery queryWithClassName:@"FriendLookup"];
[recQuery whereKey:kPULLookupReceivingUserKey equalTo:acct];
// query that ORs the previous two together and adds a couple more constraints
PFQuery *lookupQuery = [PFQuery orQueryWithSubqueries:@[senderQuery, recQuery]];
[lookupQuery whereKey:@"isBlocked" equalTo:@NO];
[lookupQuery whereKey:@"isAccepted" equalTo:@YES];
如果我只运行 lookupQuery
,它会返回当前用户是发送者或接收者的正确行。我想将该行数组作为 User 对象而不是 FriendLookup 对象。
注意 PULUser
是PFUser
的子类
// query for user where sending user key matches OID
PFQuery *userQuerySender = [PULUser query];
[userQuerySender whereKey:@"objectId" matchesKey:kPULLookupSendingUserKey inQuery:lookupQuery];
// query for user where receiving user key matches OID
PFQuery *userQueryRec = [PULUser query];
[userQueryRec whereKey:@"objectId" matchesKey:kPULLookupReceivingUserKey inQuery:lookupQuery];
// join queries together in an OR
PFQuery *query = [PFQuery orQueryWithSubqueries:@[userQuerySender, userQueryRec]];
// exclude self user from query
[query whereKey:@"objectId" notEqualTo:acct.objectId];
这将返回一个空数组。关于如何正确形成此查询的任何想法?或者是否有一种不同的方法来存储友谊可以使这项任务更容易。
最佳答案
使用include key使查询结果包含指向2个用户的指针,然后将所有用户组成一个集合并删除当前用户,然后您将拥有所有用户而无需进行二次查询。
关于ios - 从查找表中解析查询对象,我们在Stack Overflow上找到一个类似的问题: https://stackoverflow.com/questions/32851139/