Parse.com 防止无法对类型进行比较查询:(空)
Parse.com prevent Cannot do a comparison query for type: (null)
我想阻止消息“Cannot do a comparison query for type: (null)
”我不想解决它,因为我知道出了什么问题,但我想例外。如果查询没有找到任何东西...... NSLog 的东西。 (而不是崩溃)
这是我的代码:
PFQuery *requestsToCurrentUser = [PFQuery queryWithClassName:@"FriendRequest"];
[requestsToCurrentUser whereKey:@"to" equalTo:self.currentUser];
[requestsToCurrentUser whereKey:@"status" equalTo:@"pending"];
[requestsToCurrentUser findObjectsInBackgroundWithBlock:^(NSArray *objects, NSError *error) {
if (!error) {
//this property stores the data for the tableView
self.friendRequests = objects;
//reload the table
[self.tableView reloadData];
} else {
//error occcurred
}
}];
试着把这个
if(!self.currentUser){
// No value in self.currentUser
return;
}
PFQuery *requestsToCurrentUser = [PFQuery queryWithClassName:@"FriendRequest"];
[requestsToCurrentUser whereKey:@"to" equalTo:self.currentUser];
[requestsToCurrentUser whereKey:@"status" equalTo:@"pending"];
[requestsToCurrentUser findObjectsInBackgroundWithBlock:^(NSArray *objects, NSError *error) {
if (!error) {
//this property stores the data for the tableView
self.friendRequests = objects;
//reload the table
[self.tableView reloadData];
} else {
//error occcurred
}
}];
我想阻止消息“Cannot do a comparison query for type: (null)
”我不想解决它,因为我知道出了什么问题,但我想例外。如果查询没有找到任何东西...... NSLog 的东西。 (而不是崩溃)
这是我的代码:
PFQuery *requestsToCurrentUser = [PFQuery queryWithClassName:@"FriendRequest"];
[requestsToCurrentUser whereKey:@"to" equalTo:self.currentUser];
[requestsToCurrentUser whereKey:@"status" equalTo:@"pending"];
[requestsToCurrentUser findObjectsInBackgroundWithBlock:^(NSArray *objects, NSError *error) {
if (!error) {
//this property stores the data for the tableView
self.friendRequests = objects;
//reload the table
[self.tableView reloadData];
} else {
//error occcurred
}
}];
试着把这个
if(!self.currentUser){
// No value in self.currentUser
return;
}
PFQuery *requestsToCurrentUser = [PFQuery queryWithClassName:@"FriendRequest"];
[requestsToCurrentUser whereKey:@"to" equalTo:self.currentUser];
[requestsToCurrentUser whereKey:@"status" equalTo:@"pending"];
[requestsToCurrentUser findObjectsInBackgroundWithBlock:^(NSArray *objects, NSError *error) {
if (!error) {
//this property stores the data for the tableView
self.friendRequests = objects;
//reload the table
[self.tableView reloadData];
} else {
//error occcurred
}
}];