【发布时间】：2012-02-18 01:53:44
【问题描述】：
当我尝试保存我的 CoreData 模型的上下文时，我收到一个错误
Unresolved error Error Domain=NSCocoaErrorDomain Code=1560 "The operation couldn’t be completed. (Cocoa error 1560.)" UserInfo=0x76924b0 {NSDetailedErrors=(
"Error Domain=NSCocoaErrorDomain Code=1570 "
The operation couldn\U2019t be completed. (Cocoa error 1570.)"
UserInfo=0x768c410 {NSValidationErrorObject=<Posts: 0x7177990> (entity: Posts; id: 0x7177010 <x-coredata:///Posts/tEF7138E6-A968-45B7-95CF-116C2AA93D605> ; data: {\n "
business_entity"
= nil;\n "
created_at"
= "
2012-01-21 03:31:30 +0000"
;\n "
own_description"
= "
Roasted this morning- Panama Duncan Estate: A rose fragrance debuts flavors of pear, coconut and marshmallow with caramel throughout the cup."
;\n postsID = 4;\n "
updated_at"
= "
2012-01-21 03:31:30 +0000"
;\n}), NSValidationErrorKey=business_entity, NSLocalizedDescription=The operation couldn\U2019t be completed. (Cocoa error 1570.)}",
关键部分是：
business_entity = nil;
NSValidationErrorKey=business_entity
但是，当我创建“帖子”对象时，我将它们设置为：
// First try to find a business for the post
NSNumber* businessID = [NSNumber numberWithInteger: [(NSString*)[jsonInfo objectForKey:@"business_id"] integerValue]];
NSFetchRequest *fetchRequest = [[NSFetchRequest alloc] init];
[fetchRequest setEntity: [NSEntityDescription entityForName:kCoreDataModelNameBusinesses inManagedObjectContext: self.managedObjectContext]];
[fetchRequest setPredicate: [NSPredicate predicateWithFormat:@"(businessesID == %i)", [businessID intValue]]];
NSError *error = nil;
NSArray *matchingManagedObjects = [__managedObjectContext executeFetchRequest:fetchRequest error:&error];
if(error) {
NSLog(@"Error-createNewPostsWithJsonInfo: Unresolved error %@, %@", error, [error userInfo] );
return;
}
// Check any results
if( [matchingManagedObjects count] == 0) {
NSLog(@"Error-createNewPostsWithJsonInfo: Could not locate a matching businessId: %@ for postId:%@", businessID, (NSString*)[jsonInfo objectForKey:@"id"]);
}
// Check too many results
if( [matchingManagedObjects count] > 1) {
NSLog(@"Error-createNewPostsWithJsonInfo: Too many bussinesses match businessId: %@ for postId:%@", businessID, (NSString*)[jsonInfo objectForKey:@"id"]);
}
// Final sanity check outputs fine!!
NSLog(@"Business entity %@", (Businesses*)[matchingManagedObjects objectAtIndex:0] );
// Finally create the post
Posts* newPosts = [NSEntityDescription
insertNewObjectForEntityForName:entityName inManagedObjectContext:self.managedObjectContext];
newPosts.created_at = [_dateFormater dateFromString: [jsonInfo objectForKey:@"created_at"] ];
newPosts.updated_at = [_dateFormater dateFromString: [jsonInfo objectForKey:@"updated_at"] ];
newPosts.own_description = [jsonInfo objectForKey:@"description"];
newPosts.postsID = [NSNumber numberWithInteger: [(NSString*)[jsonInfo objectForKey:@"id"] integerValue]];
[newPosts setBusiness_entity: (Businesses*)[matchingManagedObjects objectAtIndex:0] ];
所以我知道正在设置 business_entity，并且是正确的。 在这种情况下保存上下文时，什么会导致它出错？
如果有帮助，这里是模型：
【问题讨论】：
-
business_entity 是关系还是属性>
标签： iphone core-data xcode4 ios5 nsmanagedobjectcontext