IOS解析如何從基於兩個類的查詢中檢索對象？

Question

我有兩個類User和Post。 User類有一個userType字段，我想檢索給定的所有帖子userType讓我們稱它們爲組x。在Post類中，我有一個指向User類的指針。

我試圖做這樣的事情，首先檢索所有用戶ID爲我要的用戶類型：

PFQuery *queryUser = [PFQuery queryWithClassName:kFTUserClassKey]; 
[queryUser whereKey:kFTUserTypeKey equalTo:kFTUserTypeX]; 
[queryUser whereKey:kFTUserLocationKey nearGeoPoint:nearGeoPoint withinMiles:miles]; 
[queryUser findObjectsInBackgroundWithBlock:^(NSArray *usersTypeX, NSError *error) { 
      if (!error) { 
       NSMutableArray *objectIds = [[NSMutableArray alloc] init]; 

       // Add ambassador ids into query 
       for (PFObject *userX in usersTypeX) { 
        [objectIds addObject:[PFObject objectWithoutDataWithClassName:kFTUserClassName objectId: userX.objectId]]; 
       } 
      } 
}]; 

然後我想基於這些的ObjectID查詢，但我不知道如何查詢在這個數組上，或者如果這是甚至正確的方式來做到這一點。如何才能做到這一點？

Answer 1

解析提供查詢matchesQuery方法，所以......

PFQuery *innerQuery = [PFQuery queryWithClassName:@"User"]; 
[innerQuery whereKey:@"userType" equalTo:@"X"]; // fix with your real user type 
PFQuery *query = [PFQuery queryWithClassName:@"Post"]; 
[query whereKey:@"user" matchesQuery:innerQuery]; 
[query findObjectsInBackgroundWithBlock:^(NSArray *posts, NSError *error) { 
    // posts are posts where post.user.userType == X 
}];