基于iOS Realm數據庫的使用實例詳解

更新時間：2018年01月20日 10:44:54 作者：鍵盤舞者113

下面小編就為大家分享一篇基于iOS Realm數據庫的使用實例詳解，具有很好的參考價值，希望對大家有所幫助。一起跟隨小編過來看看吧

首先下載Realm源代碼，https://realm.io/cn/docs/objc/latest

將下載的文件解壓，從 ios/static/ 目錄中將 Realm.framework 拖曳到 Xcode 工程的文件導航器內，然后在 Xcode 文件導航器中選中工程。然后選擇應用目標，前往 Build Phases 選項卡。在 Link Binary with Libraries 部分中單擊 + 按鈕，然后添加 libc++.tbd 和 libz.tbd。這樣還沒有完，我們還需要安裝插件，打開解壓文件夾下的plugin，運行RealmPlugin.xcodeproj，然后重啟XCode。

這樣環(huán)境配置就完了，現在說重點如何去使用。

1.創(chuàng)建實體類

new File翻到最下面點擊創(chuàng)建Realm實體類

#import <Realm/Realm.h>
@interface TestBean : RLMObject
@property NSString* name;
@property NSInteger age;

@end
// This protocol enables typed collections. i.e.:
// RLMArray<TestBean *><TestBean>
RLM_ARRAY_TYPE(TestBean)
#import "TestBean.h"
@implementation TestBean

@end

2.增刪改查

這個增加，可以看到直接添加實體類就行了，這個RLMRealm就是數據庫的操作類，以后所有操作都靠他。

-(void)addAction{
 NSLog(@"add");
 self.name = _tf_name.text;
 self.age = [_tf_age.text integerValue];

 TestBean* bean = [[TestBean alloc]init];
 bean.name = self.name;
 bean.age = self.age;
 RLMRealm *realm = [RLMRealm defaultRealm];
 [realm transactionWithBlock:^{
  [realm addObject:bean];
 }];

}

刪除也是通過刪除實體類來實現，但是我們需要首先通過查詢出實體類才行。這個查詢我們可以看到通過我們創(chuàng)建的實體類就能實現

-(void)deleteAction{

 NSLog(@"delete");
 RLMResults *dogs = [TestBean allObjects];
 RLMRealm *realm = [RLMRealm defaultRealm];
 [realm transactionWithBlock:^{
  for (TestBean *bean in dogs) {
   [realm deleteObject:bean];
  }
 }];
}

更新也是通過改變實體類的數據來實現

-(void)updateAction{
 NSLog(@"update");
 RLMResults *dogs = [TestBean allObjects];
 [[RLMRealm defaultRealm] transactionWithBlock:^{
  for (TestBean *bean in dogs) {
   bean.name = @"李四";
  }
 }];
}

查詢我們還可以添加條件

// 使用斷言字符串來查詢
RLMResults<Dog *> *tanDogs = [Dog objectsWhere:@"color = 'tan' AND name BEGINSWITH 'B'"];
// 使用 NSPredicate 來查詢
NSPredicate *pred = [NSPredicate predicateWithFormat:@"color = %@ AND name BEGINSWITH %@",
              @"tan", @"B"];
tanDogs = [Dog objectsWithPredicate:pred];

3.排序

這個是在查詢完后去實現，通過實體類的key來排序。

-(void)sortAction{
 NSLog(@"query");
 RLMResults *dogs = [[TestBean allObjects] sortedResultsUsingKeyPath:@"name" ascending:YES];
 [[RLMRealm defaultRealm] transactionWithBlock:^{
  for (TestBean *bean in dogs) {
   NSLog(@"%@",bean.name);
  }
 }];

}

4.小結

只說了常用的功能，貼上官方中文文檔供大家參考

https://realm.io/cn/docs/objc/latest

5.例子代碼

//
// ViewController.m
// BmobTest
//
// Created by shanreal-iOS on 2017/12/9.
// Copyright © 2017年 shanreal.LongZhenHao. All rights reserved.
//
#import "ViewController.h"
#import "TestBean.h"
@interface ViewController ()
@property(nonatomic,strong)UIButton* add;
@property(nonatomic,strong)UIButton* delete;
@property(nonatomic,strong)UIButton* update;
@property(nonatomic,strong)UIButton* query;
@property(nonatomic,strong)UIButton* sort;

@property(nonatomic,strong)NSString* name;
@property(nonatomic,assign)NSInteger* age;
@property(nonatomic,strong)UITextField* tf_name;
@property(nonatomic,strong)UITextField* tf_age;
@end
@implementation ViewController
- (void)viewDidLoad {
 [super viewDidLoad];
 // Do any additional setup after loading the view, typically from a nib.

 _add = [[UIButton alloc]initWithFrame:CGRectMake(10, 30, 100, 20)];
 [_add setTitle:@"add" forState:UIControlStateNormal];
 [_add setTitleColor:[UIColor blackColor] forState:UIControlStateNormal];
 [_add addTarget:self action:@selector(addAction) forControlEvents:UIControlEventTouchUpInside];
 _delete = [[UIButton alloc]initWithFrame:CGRectMake(10, 60, 100, 20)];
 [_delete setTitle:@"delete" forState:UIControlStateNormal];
 [_delete setTitleColor:[UIColor blackColor] forState:UIControlStateNormal];
 [_delete addTarget:self action:@selector(deleteAction) forControlEvents:UIControlEventTouchUpInside];
 _update = [[UIButton alloc]initWithFrame:CGRectMake(10, 90, 100, 20)];
 [_update setTitle:@"update" forState:UIControlStateNormal];
 [_update setTitleColor:[UIColor blackColor] forState:UIControlStateNormal];
 [_update addTarget:self action:@selector(updateAction) forControlEvents:UIControlEventTouchUpInside];

 _query = [[UIButton alloc]initWithFrame:CGRectMake(10, 120, 100, 20)];
 [_query setTitle:@"query" forState:UIControlStateNormal];
 [_query setTitleColor:[UIColor blackColor] forState:UIControlStateNormal];
 [_query addTarget:self action:@selector(queryAction) forControlEvents:UIControlEventTouchUpInside];
 _sort = [[UIButton alloc]initWithFrame:CGRectMake(10, 150, 100, 20)];
 [_sort setTitle:@"sort" forState:UIControlStateNormal];
 [_sort setTitleColor:[UIColor blackColor] forState:UIControlStateNormal];
 [_sort addTarget:self action:@selector(sortAction) forControlEvents:UIControlEventTouchUpInside];

 _tf_name = [[UITextField alloc]initWithFrame:CGRectMake(50, 300, 200, 20)];
 _tf_name.placeholder=@"name";
 _tf_age = [[UITextField alloc]initWithFrame:CGRectMake(50, 350, 200, 20)];
 _tf_age.placeholder=@"age";
 [self.view addSubview:_add];
 [self.view addSubview:_delete];
 [self.view addSubview:_update];
 [self.view addSubview:_query];
 [self.view addSubview:_sort];
 [self.view addSubview:_tf_name];
 [self.view addSubview:_tf_age];
}
-(void)addAction{
 NSLog(@"add");
 self.name = _tf_name.text;
 self.age = [_tf_age.text integerValue];

 TestBean* bean = [[TestBean alloc]init];
 bean.name = self.name;
 bean.age = self.age;
 RLMRealm *realm = [RLMRealm defaultRealm];
 [realm transactionWithBlock:^{
  [realm addObject:bean];
 }];

}
-(void)deleteAction{

 NSLog(@"delete");
 RLMResults *dogs = [TestBean allObjects];
 RLMRealm *realm = [RLMRealm defaultRealm];
 [realm transactionWithBlock:^{
  for (TestBean *bean in dogs) {
   [realm deleteObject:bean];
  }
 }];
}
-(void)updateAction{
 NSLog(@"update");
 RLMResults *dogs = [TestBean allObjects];
 [[RLMRealm defaultRealm] transactionWithBlock:^{
  for (TestBean *bean in dogs) {
   bean.name = @"李四";
  }
 }];
}
-(void)queryAction{
 NSLog(@"query");
 RLMResults *dogs = [TestBean allObjects];
 [[RLMRealm defaultRealm] transactionWithBlock:^{
  for (TestBean *bean in dogs) {
   NSLog(@"%@",bean.name);
  }
 }];

}
-(void)sortAction{
 NSLog(@"query");
 RLMResults *dogs = [[TestBean allObjects] sortedResultsUsingKeyPath:@"name" ascending:YES];
 [[RLMRealm defaultRealm] transactionWithBlock:^{
  for (TestBean *bean in dogs) {
   NSLog(@"%@",bean.name);
  }
 }];

}
- (void)didReceiveMemoryWarning {
 [super didReceiveMemoryWarning];
 // Dispose of any resources that can be recreated.
}

@end

以上這篇基于iOS Realm數據庫的使用實例詳解就是小編分享給大家的全部內容了，希望能給大家一個參考，也希望大家多多支持腳本之家。

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