我有表名"事件".在该表中,我有一个string类型的列.我正在努力解决如何从该列中仅删除一个元素的问题.考虑下面的图像,我想从"usersIncluded"列中删除所有出现的"iYYeR2a2rU",而不删除行.我用过了removeObject:(id) forKey:(NSString *)它并没有用.

这就是我试图实现它的方式:
PFQuery *query = [PFQuery queryWithClassName:@"Events"];
NSArray *eventObjects = [query findObjects];
[query whereKey:@"usersIncluded" equalTo:[self.uniqeFriendList objectAtIndex:indexPath.row]];
[query findObjectsInBackgroundWithBlock:^(NSArray *objects, NSError *error){
for (int i = 0; i<objects.count; i++) {
PFObject *event = [eventObjects objectAtIndex:i];
[event removeObject:[self.uniqeFriendList objectAtIndex:indexPath.row] forKey:@"usersIncluded"];
}
}];
}
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这self.uniqeFriendList是一个可变数组,包含我要从'usersIncluded'列中删除的ID.
提前致谢