CoreData基本使用-01-CoreData
// // ViewController.m // 01-CoreData基本使用 // // Created by mac on 16/5/4. // Copyright © 2016年 mac. All rights reserved. // #import "ViewController.h" #import <CoreData/CoreData.h> #import "User.h" @interface ViewController () @end @implementation ViewController { NSManagedObjectContext *_managerObjectContext; } - (void)viewDidLoad { [super viewDidLoad]; [self openDataBase]; [self addUser]; [self searchUserWithUserID:55]; NSLog(@"---------%@", NSHomeDirectory()); } /** * 1. 打开数据库 */ - (void)openDataBase { //1. 创建数据库文件 NSString *dataBaseFilePath = [NSHomeDirectory() stringByAppendingPathComponent:@"Documents/User.sqlite"]; NSURL *dataBaseFileUrl = [NSURL fileURLWithPath:dataBaseFilePath]; //2. 创建模型描述文件 /** a. 创建模型描述文件 b. */ //3. 获取模型描述文件路径 NSURL *entityFileURL = [[NSBundle mainBundle] URLForResource:@"UserModel" withExtension:@"momd"]; NSLog(@"%@", entityFileURL); //4. 通过模型描述文件 来创建pcs(持久化存储坐标) NSManagedObjectModel *model = [[NSManagedObjectModel alloc] initWithContentsOfURL:entityFileURL];// model NSPersistentStoreCoordinator *pcs = [[NSPersistentStoreCoordinator alloc] initWithManagedObjectModel:model]; //5.创建实体数据库文件 NSError *error = nil; [pcs addPersistentStoreWithType:NSSQLiteStoreType configuration:NULL URL:dataBaseFileUrl options:nil error:&error]; if (error) { NSLog(@"失败"); } else { NSLog(@"成功"); } _managerObjectContext = [[NSManagedObjectContext alloc] initWithConcurrencyType:NSMainQueueConcurrencyType]; _managerObjectContext.persistentStoreCoordinator = pcs; } /** * 2. 添加用户对象 */ - (void)addUser { /* //1. 创建MO对象并且添加到objectContext // User *user1 = [[User alloc] init]; User *user1 = (User *)[NSEntityDescription insertNewObjectForEntityForName:@"User" inManagedObjectContext:_managerObjectContext]; //2. 使用context 将数据存储到数据库 user1.username = @"zhangsan"; user1.password = @"1234"; user1.user_id = @1001; //3. 使用context将数据存储到数据库 NSError *error = nil; [_managerObjectContext save:&error]; if (error) { NSLog(@"保存失败%@", error); } else { NSLog(@"保存成功"); } */ for (int i=0; i<100; i++) { User *user = [NSEntityDescription insertNewObjectForEntityForName:@"User" inManagedObjectContext:_managerObjectContext]; user.username = [NSString stringWithFormat:@"user%i", i]; user.user_id = @(i); user.password = @"123456"; //使用context将数据存储到数据库 NSError *error = nil; [_managerObjectContext save:&error]; if (error) { NSLog(@"保存失败"); } else { NSLog(@"保存成功"); } } } /** * 3. 查询 */ - (void)searchUserWithUserID:(NSInteger)userID { //1. 构建查询请求 NSFetchRequest *fetchRequest = [NSFetchRequest fetchRequestWithEntityName:@"User"]; //2. 设置查询的条件 //3. 使用谓词来设定查询的条件 NSPredicate *predicate = [NSPredicate predicateWithFormat:@"user_id>%li",userID]; fetchRequest.predicate = predicate; //4. 执行查询请求 NSError *error = nil; NSArray *resultArray = [_managerObjectContext executeFetchRequest:fetchRequest error:&error]; //5. 处理查询结果 if (error) { NSLog(@"查询出错%@", error); } else { //查询成功 for (User *user in resultArray) NSLog(@"name = %@, password = %@, user_id = %@", user.username, user.password, user.user_id); } } @end
时光见证了成长,还很无知,我想一点点幼稚转为有知!