1 NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory,NSUserDomainMask,YES);
2 NSString *dd = [paths objectAtIndex:0];

1 NSString *tempPath = NSTemporaryDirectory();

1 NSUserDefaults *defaults = [NSUserDefaults standardUserDefaults];

 1 //使用属性列表保存3个用户的账号密码
 2     accountList = [[NSMutableArray alloc] init];
 3     [accountList addObject:[NSDictionary
 4                                 dictionaryWithObjects:[NSArray arrayWithObjects:@"loginname",@"loginpwd", nil]
 5                                 forKeys:[NSArray arrayWithObjects:@"305213781",@"123123", nil]]];
 6     [accountList addObject:[NSDictionary
 7                             dictionaryWithObjects:[NSArray arrayWithObjects:@"loginname",@"loginpwd", nil]
 8                             forKeys:[NSArray arrayWithObjects:@"475782389",@"123456", nil]]];
 9     [accountList addObject:[NSDictionary
10                             dictionaryWithObjects:[NSArray arrayWithObjects:@"loginname",@"loginpwd", nil]
11                             forKeys:[NSArray arrayWithObjects:@"330577588",@"123456789", nil]]];
12     [accountList writeToFile:[self filePath] atomically:YES];
13
14     //使用UIActionSheet提示用户保存成功
15     UIActionSheet *sheet =[[UIActionSheet alloc] initWithTitle:@"保存成功" delegate:nil cancelButtonTitle:nil destructiveButtonTitle:@"确定" otherButtonTitles:nil, nil];
16     [sheet showInView:self.view];

 1 #pragma mark - Core Data stack
 2
 3 @synthesize managedObjectContext = _managedObjectContext;
 4 @synthesize managedObjectModel = _managedObjectModel;
 5 @synthesize persistentStoreCoordinator = _persistentStoreCoordinator;
 6
 7 - (NSURL *)applicationDocumentsDirectory {
 8     // The directory the application uses to store the Core Data store file. This code uses a directory named "esitech.Unit_3" in the application's documents directory.
 9     return [[[NSFileManager defaultManager] URLsForDirectory:NSDocumentDirectory inDomains:NSUserDomainMask] lastObject];
10 }
11
12 - (NSManagedObjectModel *)managedObjectModel {
13     // The managed object model for the application. It is a fatal error for the application not to be able to find and load its model.
14     if (_managedObjectModel != nil) {
15         return _managedObjectModel;
16     }
17     //获取实体模型文件对应的nsurl
18     NSURL *modelURL = [[NSBundle mainBundle] URLForResource:@"Unit_3" withExtension:@"momd"];
19     _managedObjectModel = [[NSManagedObjectModel alloc] initWithContentsOfURL:modelURL];
20     return _managedObjectModel;
21 }
22
23 - (NSPersistentStoreCoordinator *)persistentStoreCoordinator {
24     // The persistent store coordinator for the application. This implementation creates and return a coordinator, having added the store for the application to it.
25     if (_persistentStoreCoordinator != nil) {
26         return _persistentStoreCoordinator;
27     }
28
29     // Create the coordinator and store
30     //以持久化模型为基础，创建持久化存储协调器对象
31     _persistentStoreCoordinator = [[NSPersistentStoreCoordinator alloc] initWithManagedObjectModel:[self managedObjectModel]];
32     //获取sqlite数据库文件的存储目录
33     NSURL *storeURL = [[self applicationDocumentsDirectory] URLByAppendingPathComponent:@"Unit_3.sqlite"];
34     NSError *error = nil;
35     NSString *failureReason = @"There was an error creating or loading the application's saved data.";
36     //设置存储协调器采用sqlite，如果失败打印失败信息
37     if (![_persistentStoreCoordinator addPersistentStoreWithType:NSSQLiteStoreType configuration:nil URL:storeURL options:nil error:&error]) {
38         // Report any error we got.
39         NSMutableDictionary *dict = [NSMutableDictionary dictionary];
40         dict[NSLocalizedDescriptionKey] = @"Failed to initialize the application's saved data";
41         dict[NSLocalizedFailureReasonErrorKey] = failureReason;
42         dict[NSUnderlyingErrorKey] = error;
43         error = [NSError errorWithDomain:@"YOUR_ERROR_DOMAIN" code:9999 userInfo:dict];
44         // Replace this with code to handle the error appropriately.
45         // abort() causes the application to generate a crash log and terminate. You should not use this function in a shipping application, although it may be useful during development.
46         NSLog(@"Unresolved error %@, %@", error, [error userInfo]);
47         abort();
48     }
49
50     return _persistentStoreCoordinator;
51 }
52
53
54 - (NSManagedObjectContext *)managedObjectContext {
55     // Returns the managed object context for the application (which is already bound to the persistent store coordinator for the application.)
56     if (_managedObjectContext != nil) {
57         return _managedObjectContext;
58     }
59
60     NSPersistentStoreCoordinator *coordinator = [self persistentStoreCoordinator];
61     if (!coordinator) {
62         return nil;
63     }
64     _managedObjectContext = [[NSManagedObjectContext alloc] init];
65     //设置上下文使用的持久化类型
66     [_managedObjectContext setPersistentStoreCoordinator:coordinator];
67     return _managedObjectContext;
68 }
69
70 #pragma mark - Core Data Saving support
71
72 - (void)saveContext {
73     NSManagedObjectContext *managedObjectContext = self.managedObjectContext;
74     if (managedObjectContext != nil) {
75         NSError *error = nil;
76         if ([managedObjectContext hasChanges] && ![managedObjectContext save:&error]) {
77             // Replace this implementation with code to handle the error appropriately.
78             // abort() causes the application to generate a crash log and terminate. You should not use this function in a shipping application, although it may be useful during development.
79             NSLog(@"Unresolved error %@, %@", error, [error userInfo]);
80             abort();
81         }
82     }
83 }

 1 #import "SqliteViewController.h"
 2 #import "EventEntity.h"
 3 #import <Foundation/Foundation.h>
 4 #import <CoreData/CoreData.h>
 5 #import "AppDelegate.h"
 6
 7 @interface SqliteViewController ()
 8 @property (nonatomic,weak) AppDelegate *appDelete;
 9 @property (nonatomic) int nameCount;
10 @end
11
12 @implementation SqliteViewController
13
14 - (void)viewDidLoad {
15     [super viewDidLoad];
16     self.nameCount = 1;
17     // Do any additional setup after loading the view.
18     self.appDelete = (AppDelegate *)[UIApplication sharedApplication].delegate;
19 }
20
21 - (void)didReceiveMemoryWarning {
22     [super didReceiveMemoryWarning];
23     // Dispose of any resources that can be recreated.
24 }

 1 //添加操作
 2 - (IBAction)btnAdd_Tap:(id)sender {
 3     //创建一个新实体
 4     EventEntity *ee = [NSEntityDescription insertNewObjectForEntityForName:@"EventEntity" inManagedObjectContext:self.appDelete.managedObjectContext];
 5     //给实体设置属性
 6     ee.happenDate = [NSDate date];
 7     ee.name = [NSString stringWithFormat:@"名字%d",self.nameCount++];
 8
 9     //定义NSError对象接收错误信息
10     NSError *error;
11     if ([self.appDelete.managedObjectContext save:&error]) {
12         [[[UIAlertView alloc] initWithTitle:@"添加操作" message:[NSString stringWithFormat:@"添加成功,添加的实体的name是：%@",ee.name] delegate:nil cancelButtonTitle:@"好的" otherButtonTitles:nil, nil] show];
13     }else
14     {
15         NSLog(@"保存时出现错误：%@,%@",error,[error userInfo]);
16     }
17 }

 1 //删除操作
 2 - (IBAction)btnRemove_Tap:(id)sender {
 3     //获取要删除的实体
 4     EventEntity *entity = [self getEntityByName:@"名字1"];
 5     //从上下文对象中删除该实体
 6     [self.appDelete.managedObjectContext deleteObject:entity];
 7     NSError *error;
 8     if (![self.appDelete.managedObjectContext save:&error]) {
 9         NSLog(@"删除时出现错误：%@,%@",error,[error userInfo]);
10     }
11 }

5.3 修改实体

 1 //更新操作
 2 - (IBAction)btnUpdate_Tap:(id)sender {
 3     //获取要删除的实体
 4     EventEntity *entity = [self getEntityByName:@"名字1"];
 5     //修改实体属性
 6     entity.happenDate = [NSDate date];
 7     NSError *error;
 8     if (![self.appDelete.managedObjectContext save:&error]) {
 9         NSLog(@"删除时出现错误：%@,%@",error,[error userInfo]);
10     }
11 }

5.4 查询

 1 //根据名字查询一个对象
 2 -(EventEntity *)getEntityByName:(NSString *) name
 3 {
 4     //创建抓取数据的请求对象
 5     NSFetchRequest *request = [[NSFetchRequest alloc] init];
 6
 7     //设置要抓取哪种类型的实体
 8     NSEntityDescription *des = [NSEntityDescription entityForName:@"EventEntity" inManagedObjectContext:self.appDelete.managedObjectContext];
 9
10     //设置抓取实体
11     [request setEntity:des];
12     //定义抓取条件
13     NSPredicate * qcmd = [NSPredicate predicateWithFormat:@"name = %@ ",name];
14     [request setPredicate:qcmd];
15
16     NSError *error = nil;
17     //执行查询请求
18     NSArray *result = [[self.appDelete.managedObjectContext executeFetchRequest:request error:&error] copy];
19     if (error!=nil) {
20         NSLog(@"查询单个时出现错误：%@,%@",error,[error userInfo]);
21         return nil;
22     }
23     if (result.count==0) {
24         return nil;
25     }
26     return result[0];
27 }
28
29 //获得所有实体
30 -(NSArray *)getAllEntities
31 {
32     //创建抓取数据的请求对象
33     NSFetchRequest *request = [[NSFetchRequest alloc] init];
34
35     //设置要抓取哪种类型的实体
36     NSEntityDescription *des = [NSEntityDescription entityForName:@"EventEntity" inManagedObjectContext:self.appDelete.managedObjectContext];
37
38     //设置抓取实体
39     [request setEntity:des];
40
41     NSError *error = nil;
42     //执行查询请求
43     NSArray *result = [[self.appDelete.managedObjectContext executeFetchRequest:request error:&error] copy];
44     //如果没有数据返回nil
45     if (error!=nil && result == 0) {
46         return nil;
47     }
48     return result;
49
50 }