[英]Core data save entity issue
This might be a very primitive question. 这可能是一个非常原始的问题。 I have a list of states that belongs to different countries. 我有一个属于不同国家的州清单。
Data 1: state - xyz
country - A
Data 2 : state - abc
country - B
Data 3: state - ght
country - A
Data 2 : state - ase
country - B
In core data i have differnt entities for state and country. 在核心数据中,我具有州和国家/地区的不同实体。 While saving how do i put all the states to their country object? 在保存的同时,我如何将所有州置于其国家对象上?
EDIT : Country state relation 编辑:国家/地区关系
Assuming Data is Array of Dictionary, 假设数据是字典数组,
for (NSDictionary *data in datas) {
NSFetchRequest *fetchRequest = [[NSFetchRequest alloc] init];
NSEntityDescription *entity = [NSEntityDescription entityForName:@"Country" inManagedObjectContext:[dbManager getCurrentContext]];
[fetchRequest setEntity:entity];
NSPredicate *predicate = [NSPredicate predicateWithFormat:@"name = %@", [data valueForKey:@"country"]];
[fetchRequest setPredicate:predicate];
NSError *error;
NSArray * fetchedObjects = [managedObjectContext executeFetchRequest:fetchRequest error:&error];
if ([fetchedObjects count] > 0) {
Country *country = [fetchedObjects objectAtIndex:0];
//Using CoreDataGeneratedAccessors
[country addStateObject:[data valueForKey:@"state"]];
} else {
Country *country = [NSEntityDescription insertNewObjectForEntityForName:@"Country" inManagedObjectContext:managedObjectContext];
country.name = [data valueForKey:@"country"];
...
if ([managedObjectContext save:&error])
{
//Using CoreDataGeneratedAccessors
[country addStateObject:[data valueForKey:@"state"]];
}
}
}
Hope this may help you 希望这对您有帮助
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