参考博客:

http://www.jianshu.com/p/096bec929f2a

http://www.cnblogs.com/ilyy/p/5648051.html

参考的博客介绍很详细,我就不写了..写了一个简单的学习的demo.

GitHub地址: https://github.com/PengSiSi/RealmDemo

**
**

代码如下:

//
// ViewController.m
// RealmDemo
//
// Created by 思 彭 on 2017/7/20.
// Copyright © 2017年 思 彭. All rights reserved.

// 注意区别默认的和自己自定义realm的

#import "ViewController.h"
#import "PersonModel.h"
#import
#import

@interface ViewController () {

RLMRealm \*\_customRealm;  

}

@property (weak, nonatomic) IBOutlet UITextField *nameTextField;
@property (weak, nonatomic) IBOutlet UITextField *sexTextField;
@property (weak, nonatomic) IBOutlet UITextField *ageTextField;

@property (nonatomic, strong) RLMResults *locArray;
@property (nonatomic, strong) RLMNotificationToken *token;

@end

@implementation ViewController

• (void)viewDidLoad {
  [super viewDidLoad];
  // 可以使用默认的
  // _customRealm = [RLMRealm defaultRealm];

  //自己创建一个新的RLMRealm
  NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);
  NSString *pathStr = paths.firstObject;
  // pathStr = /Users/sipeng/Library/Developer/CoreSimulator/Devices/59E51096-9523-4845-84E8-2BB5360FB50E/data/Containers/Data/Application/A20B045E-6C86-4872-99DF-A52541FB1104/Documents

  NSLog(@"pathStr = %@",pathStr);
  _customRealm = [RLMRealm realmWithURL:[NSURL fileURLWithPath:[NSString stringWithFormat:@"%@/%@",pathStr,@"person.realm"]]];
  }

/**
增

@param sender <#sender description#>
*/

• (IBAction)addAction:(id)sender {

  // 获取默认的 Realm 实例
  // RLMRealm *realm = [RLMRealm defaultRealm];

  PersonModel *person = [[PersonModel alloc]init];
  person.name = self.nameTextField.text;
  person.sex = self.sexTextField.text;
  person.age = [self.ageTextField.text integerValue];
  NSLog(@"name - %@ sex = %@ age = %ld",person.name, person.sex, person.age);
  // 数据持久化
  [_customRealm transactionWithBlock:^{
  [_customRealm addObject:person];
  }];
  // 通过事务将数据添加到 Realm 中
  // [_customRealm beginWriteTransaction];
  // [_customRealm addObject:person];
  // [_customRealm commitWriteTransaction];
  NSLog(@"增加成功啦");
  [self findAction:nil];
  }

/**
删

@param sender <#sender description#>
*/

• (IBAction)deleteAction:(id)sender {

  // 获取默认的 Realm 实例
  // RLMRealm *realm = [RLMRealm defaultRealm];
  [_customRealm beginWriteTransaction];
  [_customRealm deleteAllObjects];
  [_customRealm commitWriteTransaction];
  [self findAction:nil];
  }

/**
改

@param sender <#sender description#>
*/

• (IBAction)updateAction:(id)sender {

  for (PersonModel *person in self.locArray) {
  NSLog(@"name - %@ sex = %@ age = %ld",person.name, person.sex, person.age);
  }

  // 获取默认的 Realm 实例
  // RLMRealm *realm = [RLMRealm defaultRealm];
  PersonModel *model = self.locArray[];
  [_customRealm beginWriteTransaction];
  model.name = @"思思棒棒哒";
  [_customRealm commitWriteTransaction];

  NSLog(@"修改成功");
  for (PersonModel *person in self.locArray) {
  NSLog(@"name - %@ sex = %@ age = %ld",person.name, person.sex, person.age);
  }
  }

/**
查

@param sender <#sender description#>
*/

• (IBAction)findAction:(id)sender {

  //自己创建一个新的RLMRealm
  NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);
  NSString *pathStr = paths.firstObject;
  NSLog(@"pathStr = %@",pathStr);

  // 查询指定的 Realm 数据库
  RLMRealm *personRealm = [RLMRealm realmWithURL:[NSURL fileURLWithPath:[NSString stringWithFormat:@"%@/%@",pathStr,@"person.realm"]]];
  // 获得一个指定的 Realm 数据库
  self.locArray = [PersonModel allObjectsInRealm:personRealm]; // 从该 Realm 数据库中，检索所有model

  // 这是默认查询默认的realm
  // self.locArray = [PersonModel allObjects];
  NSLog(@"self.locArray.count = %ld",self.locArray.count);
  }

// 创建数据库

• (void)creatDataBaseWithName:(NSString *)databaseName{

  NSArray *docPath = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);
  NSString *path = [docPath objectAtIndex:];
  NSString *filePath = [path stringByAppendingPathComponent:databaseName];
  NSLog(@"数据库目录 = %@",filePath);

  RLMRealmConfiguration *config = [RLMRealmConfiguration defaultConfiguration];
  config.fileURL = [NSURL URLWithString:filePath];
  // config.objectClasses = @[MyClass.class, MyOtherClass.class];
  config.readOnly = NO;
  int currentVersion = 1.0;
  config.schemaVersion = currentVersion;

  config.migrationBlock = ^(RLMMigration *migration , uint64_t oldSchemaVersion) { // 这里是设置数据迁移的block
  if (oldSchemaVersion < currentVersion) {
  }
  };

  [RLMRealmConfiguration setDefaultConfiguration:config];
  }

@end