create pfobject relation

relation.m

PFObject *myPost = [PFObject objectWithClassName:@"Post"];
[myPost setObject:@"I'm Hungry" forKey:@"title"];
[myPost setObject:@"Where should we go for lunch?" forKey:@"content"];

// Create the comment
PFObject *myComment = [PFObject objectWithClassName:@"Comment"];
[myComment setObject:@"Let's do Sushirrito." forKey:@"content"];

// Add a relation between the Post and Comment
[myComment setObject:myPost forKey:@"parent"];

// This will save both myPost and myComment
[myComment saveInBackground];