CoreData 本地数据存储

 1 /*
 2  * CoreData数据管理类
 3  * CoreDataManager.h
 4  */
 5 
 6 #import <Foundation/Foundation.h>
 7 #import <CoreData/CoreData.h>
 8 
 9 #define DATA_FILE   @"date.date"
10 #define ENTITY_NAME @"Country"
11 #define SORT_KEY    @"key"
12 #define ADD_DATA     YES
13 #define CHANGE_DATA  NO
14 
15 @interface CoreDataManager : NSObject
16 // 数据管理模型
17 @property(nonatomic,strong)NSManagedObjectModel *model;
18 // 数据管理上下文
19 @property(nonatomic,strong)NSManagedObjectContext *context;
20 // 持久存储
21 @property(nonatomic,strong)NSPersistentStore *store;
22 // 持久化存储协调者
23 @property(nonatomic,strong)NSPersistentStoreCoordinator *psc;
24 
25 // 单例
26 + (instancetype)shareInstance;
27 
28 /*
29  * 搭建数据管理上下文
30  */
31 - (void)contextBuilding;
32 
33 /*
34  * 查询所有数据并返回数据数组
35  */
36 - (NSArray*)read;
37 
38 /*
39  * 添加/更新数据
40  */
41 - (void)updataWithKey:(NSInteger)key country:(NSString*)country capital:(NSString *)capital population:(NSInteger)population area:(double)area;
42 
43 /*
44  * 删除数据
45  */
46 - (void)deleteWithKey:(NSInteger)key;
47 
48 
49 @end

  1 // CoreDataManager.m
  2 
  3 #import "CoreDataManager.h"
  4 #import "Country.h"
  5 
  6 CoreDataManager *manager = nil;
  7 @implementation CoreDataManager
  8 
  9 #pragma mark - 单例
 10 + (instancetype)shareInstance{
 11     if(!manager){
 12         static dispatch_once_t onceToken;
 13         dispatch_once(&onceToken, ^{
 14             manager = [CoreDataManager new];
 15         });
 16     }
 17     return manager;
 18 }
 19 
 20 #pragma mark - 构建管理上下文
 21 - (void)contextBuilding{
 22     // 从程序包中加载应用文件
 23     self.model = [NSManagedObjectModel mergedModelFromBundles:nil];
 24     // 传入模型文件并初始化
 25     self.psc = [[NSPersistentStoreCoordinator alloc] initWithManagedObjectModel:self.model];
 26     // 构建数据文件路径
 27     NSString *docPath = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES)[0];
 28     NSURL *dataUrl = [NSURL fileURLWithPath:[docPath stringByAppendingPathComponent:DATA_FILE]];
 29     // 添加持久化数据库
 30     NSError *error = nil;
 31     self.store = [self.psc addPersistentStoreWithType:NSSQLiteStoreType configuration:nil URL:dataUrl options:nil error:&error];
 32     // 判断数据库是否创建成功
 33     if(!self.store){
 34         [NSException raise:@"添加数据库错误" format:@"%@", [error localizedDescription]];
 35     }
 36     // 在多线程中设置上下文
 37     self.context = [[NSManagedObjectContext alloc] initWithConcurrencyType:NSPrivateQueueConcurrencyType];
 38     self.context.persistentStoreCoordinator = self.psc;
 39 }
 40 
 41 #pragma mark - 查询所有数据
 42 - (NSArray *)read{
 43     NSFetchRequest *fetchRequest = [[NSFetchRequest alloc] init];
 44     NSEntityDescription *entity = [NSEntityDescription entityForName:ENTITY_NAME inManagedObjectContext:self.context];
 45     [fetchRequest setEntity:entity];
 46     // Specify criteria for filtering which objects to fetch
 47 //    NSPredicate *predicate = [NSPredicate predicateWithFormat:@"<#format string#>", <#arguments#>];
 48 //    [fetchRequest setPredicate:predicate];
 49     // Specify how the fetched objects should be sorted
 50     // 设置排序关键字
 51     NSSortDescriptor *sortDescriptor = [[NSSortDescriptor alloc] initWithKey:SORT_KEY
 52                                                                    ascending:YES];
 53     [fetchRequest setSortDescriptors:[NSArray arrayWithObjects:sortDescriptor, nil]];
 54     
 55     NSError *error = nil;
 56     NSArray *fetchedObjects = [self.context executeFetchRequest:fetchRequest error:&error];
 57     if (fetchedObjects == nil) {
 58         [NSException raise:@"查询数据库错误" format:@"%@", [error localizedDescription]];
 59     }
 60     return fetchedObjects;
 61 }
 62 
 63 #pragma mark - 添加数据
 64 - (void)updataWithKey:(NSInteger)key country:(NSString*)country capital:(NSString *)capital population:(NSInteger)population area:(double)area{
 65     // CoreData不支持主键，故在进行添加修改数据时务必做判断(手动设置主键)
 66     NSError *error = nil;
 67     NSArray *array = [self read];
 68     BOOL dataHandle = ADD_DATA;
 69     // 判断主键是否重复，是则更新，否则添加
 70     for(Country *model in array){
 71         if([[model valueForKey:SORT_KEY] isEqual:@(key)]){
 72             model.name = country;
 73             model.population = @(population);
 74             model.area = @(area);
 75             model.capital = capital;
 76             if(![self.context save:&error]){
 77                 [NSException raise:@"数据更新错误" format:@"%@", [error localizedDescription]];
 78             }
 79             dataHandle = CHANGE_DATA;
 80         }
 81     }
 82     
 83     // 添加
 84     if(dataHandle == ADD_DATA){
 85         // 创建对象
 86         Country *model = [NSEntityDescription insertNewObjectForEntityForName:ENTITY_NAME inManagedObjectContext:self.context];
 87         model.key = @([((Country*)[array lastObject]).key integerValue] + 1);
 88         model.name = country;
 89         model.capital = capital;
 90         model.population = @(population);
 91         model.area = @(area);
 92         if(![self.context save:&error]){
 93             [NSException raise:@"添加数据错误" format:@"%@", [error localizedDescription]];
 94         }
 95     }
 96 }
 97 
 98 #pragma mark - 删除数据
 99 - (void)deleteWithKey:(NSInteger)key{
100     NSError *error = nil;
101     NSArray *array = [self read];
102     for(Country *model in array){
103         if([model.key isEqual:@(key)]){
104             [self.context deleteObject:model];
105             if(![self.context save:&error]){
106                 [NSException raise:@"删除数据错误" format:@"%@", [error localizedDescription]];
107             }
108         }
109     }
110 }
111 
112 @end

1 /* 
2  * CoreData的版本迁移(轻量级)
3  * 需要创建自动版本迁移和自动版本映射的字典
4  */
5 
6 NSDictionary *options = @{NSMigratePersistentStoresAutomaticallyOption:@YES,NSInferMappingModelAutomaticallyOption:@YES};
7 
8 self.store = [self.psc addPersistentStoreWithType:NSSQLiteStoreType configuration:nil URL:dataUrl options:options error:&error];