ios 如何使用 NSManagedObjectSubClass 从 CoreData Base 获取所有记录？
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How to get all records From CoreData Base using NSManagedObjectSubClass?
提问by Musthafa
I am trying to implement CoreDatain iosApplication,Now I want to Fetch all records from Entity MUSTHAFA
我正在尝试CoreData在ios应用程序中实现，现在我想从实体中获取所有记录MUSTHAFA
My NSManagedObjectedSubClass is MUSTAHFA
MUSTHAFA.m
MUSTHAFA.m
#import <Foundation/Foundation.h>
#import <CoreData/CoreData.h>
@interface MUSTHAFA : NSManagedObject {
@private
}
@property (nonatomic, retain) NSString * FirstName;
@property (nonatomic, retain) NSNumber * Age;
@property (nonatomic, retain) NSString * Location;
@property (nonatomic, retain) NSString * LastName;
@end
#import "MUSTHAFA.h"
@implementation MUSTHAFA
@dynamic FirstName;
@dynamic Age;
@dynamic Location;
@dynamic LastName;
@end
Adding Records to Core Data
向核心数据添加记录
-(void)AddRecordToCoreData{
//NSLog(@"______ ADD Core Data Implementaion");
MUSTHAFA *event = (MUSTHAFA *)[NSEntityDescription insertNewObjectForEntityForName:@"MUSTHAFA" inManagedObjectContext:managedObjectContext];
[event setLastName:@"JOHN"];
[event setFirstName:@"JOSE "];
[event setLocation:@"IDUKKI "];
[event setAge:[NSNumber numberWithInt:25]];
NSError *error;
if (![managedObjectContext save:&error])
{
NSLog(@"Error..%@",error);
}
else
{
NSLog(@"Data added to MUSTHAFA ");
}
}
Retrieving all Values from Core Data just like select * from dbTable;
从核心数据中检索所有值就像 select * from dbTable;
-(void)FetchRecordFromCoreData:(id)data1{
//NSLog(@"______ Fetch Core Data Implementaion");
MUSTHAFA *event = (MUSTHAFA *)[NSEntityDescription insertNewObjectForEntityForName:@"MUSTHAFA" inManagedObjectContext:managedObjectContext];
//USING event how can fetch all record from Data base;
}
USING event (Instance of MUSTAHFA) how can fetch all record from Data base?
USING 事件（MUSTAHFA 的实例）如何从数据库中获取所有记录？
回答by Joseph DeCarlo
NSManagedObjectContext *context = //Get it from AppDelegate
NSFetchRequest *request = [[NSFetchRequest alloc]initWithEntityName:@"MUSTHAFA"];
NSError *error = nil;
NSArray *results = [context executeFetchRequest:request error:&error];
if (error != nil) {
//Deal with failure
}
else {
//Deal with success
}
[request release];
回答by Ishwar Hingu
AppDelegate *delegate = [UIApplication sharedApplication].delegate;
NSManagedObjectContext *context =[delegate managedObjectContext];
NSFetchRequest *request = [[NSFetchRequest alloc]initWithEntityName:@"Channels"];
NSError *error = nil;
NSArray *results = [context executeFetchRequest:request error:&error];
ChannelDBArray=[[NSMutableArray alloc]init];
for (NSManagedObject *obj in results) {
NSArray *keys = [[[obj entity] attributesByName] allKeys];
NSDictionary *dictionary = [obj dictionaryWithValuesForKeys:keys];
}
if (error != nil) {
//Deal with failure
}
else {
//Deal with success
}
