**Android Room 框架详解** Android Room 是Google在Android架构组件库中推出的一个数据库解决方案,它是对SQLite数据库的一种抽象层,旨在使数据操作更加简便、类型安全,并且与现代开发实践更好地集成。Room提供了更高级别的API,使得开发者可以在不牺牲性能的前提下,避免直接编写大量的SQL代码。 **1. 安装与配置** 要使用Room,首先需要在项目的build.gradle文件中添加依赖。添加以下依赖项到应用模块的dependencies块中: ```groovy implementation 'androidx.room:room-runtime:2.x.x' annotationProcessor 'androidx.room:room-compiler:2.x.x' ``` 这里的`2.x.x`需要替换为最新的版本号。 **2. 数据库实体(Entities)** 在Room中,数据模型通常表示为Java或Kotlin类,这些类称为实体(Entities)。例如,我们可以创建一个名为`User`的实体类: ```java @Entity(tableName = "users") public class User { @PrimaryKey(autoGenerate = true) public int id; @ColumnInfo(name = "name") public String name; @ColumnInfo(name = "email") public String email; } ``` 在这里,`@Entity`注解表示这是一个数据库表,`tableName`定义了表名,`@PrimaryKey`定义主键,`@ColumnInfo`指定列名。 **3. 数据访问对象(DAOs)** DAO(Data Access Object)接口定义了对数据库的操作。Room会根据这些接口自动生成实现。例如,我们可以创建一个`UserDao`接口: ```java @Dao public interface UserDao { @Insert void insert(User user); @Update void update(User user); @Delete void delete(User user); @Query("SELECT * FROM users WHERE name LIKE :name") List<User> getUsersByName(String name); } ``` 这里,`@Insert`、`@Update`、`@Delete`用于插入、更新和删除操作,`@Query`则允许我们编写自定义的SQL查询。 **4. 数据库(Database)** `RoomDatabase`是整个数据库的入口点,我们需要创建一个继承自`RoomDatabase`的抽象类,并在其中声明我们的DAO: ```java @Database(entities = {User.class}, version = 1, exportSchema = false) public abstract class AppDatabase extends RoomDatabase { public abstract UserDao userDao(); } ``` `entities`参数是数据库中包含的实体类列表,`version`是数据库的版本号,用于在升级时处理数据迁移。 **5. 全文搜索(FTS)** Room支持SQLite的全文搜索(FTS)功能,这使得可以对文本进行高效的模糊查询。要启用FTS,需要在实体类上使用`@FullTextSearchable`注解,并在表中创建一个fts4或fts5表。例如: ```java @Entity(tableName = "searchable_notes", searchIndex = @SearchIndex(name = "searchable_notes_idx", all = {"text"})) public class Note { @PrimaryKey(autoGenerate = true) public int id; @ColumnInfo(name = "text") @FullTextSearchable public String content; } ``` 然后,在DAO中,你可以创建一个`@Search`注解的方法来进行全文搜索: ```java @Search(query = "*", entity = Note.class) List<Note> search(String searchText); ``` **6. 使用与生命周期管理** 在Activity或Fragment中,我们可以通过`Room.databaseBuilder()`方法创建`AppDatabase`的实例。由于Room考虑了Android的生命周期,推荐使用`AndroidViewModel`或`ViewModel`配合`LiveData`来获取实时更新的数据,这样可以在配置变更时保持数据持久性。 Android Room提供了一种简洁、安全的方式来管理Android应用中的SQLite数据库,它的使用包括定义实体、DAO接口、数据库类,以及利用FTS功能进行全文搜索。通过结合现代的Android开发最佳实践,如MVVM模式和LiveData,Room极大地简化了数据库操作,提高了开发效率。
![rar](https://img-home.csdnimg.cn/images/20241231044955.png)
![zip](https://img-home.csdnimg.cn/images/20241231045053.png)
![rar](https://img-home.csdnimg.cn/images/20241231044955.png)
![zip](https://img-home.csdnimg.cn/images/20241231045053.png)
![zip](https://img-home.csdnimg.cn/images/20241231045053.png)
![zip](https://img-home.csdnimg.cn/images/20241231045053.png)
![zip](https://img-home.csdnimg.cn/images/20241231045053.png)
![zip](https://img-home.csdnimg.cn/images/20241231045053.png)
![zip](https://img-home.csdnimg.cn/images/20241231045053.png)
![zip](https://img-home.csdnimg.cn/images/20241231045053.png)
![zip](https://img-home.csdnimg.cn/images/20241231045053.png)
![zip](https://img-home.csdnimg.cn/images/20241231045053.png)
![zip](https://img-home.csdnimg.cn/images/20241231045053.png)
![zip](https://img-home.csdnimg.cn/images/20241231045053.png)
![zip](https://img-home.csdnimg.cn/images/20241231045053.png)
![zip](https://img-home.csdnimg.cn/images/20241231045053.png)
![zip](https://img-home.csdnimg.cn/images/20241231045053.png)
![package](https://csdnimg.cn/release/downloadcmsfe/public/img/package.f3fc750b.png)
![folder](https://csdnimg.cn/release/downloadcmsfe/public/img/folder.005fa2e5.png)
![file-type](https://csdnimg.cn/release/download/static_files/pc/images/minetype/UNKNOWN.png)
![folder](https://csdnimg.cn/release/downloadcmsfe/public/img/folder.005fa2e5.png)
![folder](https://csdnimg.cn/release/downloadcmsfe/public/img/folder.005fa2e5.png)
![file-type](https://csdnimg.cn/release/download/static_files/pc/images/minetype/JAR.png)
![file-type](https://csdnimg.cn/release/download/static_files/pc/images/minetype/UNKNOWN.png)
![folder](https://csdnimg.cn/release/downloadcmsfe/public/img/folder.005fa2e5.png)
![folder](https://csdnimg.cn/release/downloadcmsfe/public/img/folder.005fa2e5.png)
![folder](https://csdnimg.cn/release/downloadcmsfe/public/img/folder.005fa2e5.png)
![folder](https://csdnimg.cn/release/downloadcmsfe/public/img/folder.005fa2e5.png)
![file-type](https://csdnimg.cn/release/download/static_files/pc/images/minetype/TXT.png)
![file-type](https://csdnimg.cn/release/download/static_files/pc/images/minetype/TXT.png)
![folder](https://csdnimg.cn/release/downloadcmsfe/public/img/folder.005fa2e5.png)
![folder](https://csdnimg.cn/release/downloadcmsfe/public/img/folder.005fa2e5.png)
![folder](https://csdnimg.cn/release/downloadcmsfe/public/img/folder.005fa2e5.png)
![folder](https://csdnimg.cn/release/downloadcmsfe/public/img/folder.005fa2e5.png)
![folder](https://csdnimg.cn/release/downloadcmsfe/public/img/folder.005fa2e5.png)
![file-type](https://csdnimg.cn/release/download/static_files/pc/images/minetype/UNKNOWN.png)
![folder](https://csdnimg.cn/release/downloadcmsfe/public/img/folder.005fa2e5.png)
![file-type](https://csdnimg.cn/release/download/static_files/pc/images/minetype/UNKNOWN.png)
![file-type](https://csdnimg.cn/release/download/static_files/pc/images/minetype/UNKNOWN.png)
![file-type](https://csdnimg.cn/release/download/static_files/pc/images/minetype/UNKNOWN.png)
![folder](https://csdnimg.cn/release/downloadcmsfe/public/img/folder.005fa2e5.png)
![file-type](https://csdnimg.cn/release/download/static_files/pc/images/minetype/UNKNOWN.png)
![file-type](https://csdnimg.cn/release/download/static_files/pc/images/minetype/UNKNOWN.png)
![file-type](https://csdnimg.cn/release/download/static_files/pc/images/minetype/UNKNOWN.png)
![folder](https://csdnimg.cn/release/downloadcmsfe/public/img/folder.005fa2e5.png)
![folder](https://csdnimg.cn/release/downloadcmsfe/public/img/folder.005fa2e5.png)
![file-type](https://csdnimg.cn/release/download/static_files/pc/images/minetype/UNKNOWN.png)
![folder](https://csdnimg.cn/release/downloadcmsfe/public/img/folder.005fa2e5.png)
![file-type](https://csdnimg.cn/release/download/static_files/pc/images/minetype/UNKNOWN.png)
![file-type](https://csdnimg.cn/release/download/static_files/pc/images/minetype/UNKNOWN.png)
![file-type](https://csdnimg.cn/release/download/static_files/pc/images/minetype/UNKNOWN.png)
![file-type](https://csdnimg.cn/release/download/static_files/pc/images/minetype/UNKNOWN.png)
![folder](https://csdnimg.cn/release/downloadcmsfe/public/img/folder.005fa2e5.png)
![folder](https://csdnimg.cn/release/downloadcmsfe/public/img/folder.005fa2e5.png)
![folder](https://csdnimg.cn/release/downloadcmsfe/public/img/folder.005fa2e5.png)
![folder](https://csdnimg.cn/release/downloadcmsfe/public/img/folder.005fa2e5.png)
![folder](https://csdnimg.cn/release/downloadcmsfe/public/img/folder.005fa2e5.png)
![folder](https://csdnimg.cn/release/downloadcmsfe/public/img/folder.005fa2e5.png)
![folder](https://csdnimg.cn/release/downloadcmsfe/public/img/folder.005fa2e5.png)
![folder](https://csdnimg.cn/release/downloadcmsfe/public/img/folder.005fa2e5.png)
![folder](https://csdnimg.cn/release/downloadcmsfe/public/img/folder.005fa2e5.png)
![file-type](https://csdnimg.cn/release/download/static_files/pc/images/minetype/UNKNOWN.png)
![file-type](https://csdnimg.cn/release/download/static_files/pc/images/minetype/UNKNOWN.png)
![folder](https://csdnimg.cn/release/downloadcmsfe/public/img/folder.005fa2e5.png)
![folder](https://csdnimg.cn/release/downloadcmsfe/public/img/folder.005fa2e5.png)
![file-type](https://csdnimg.cn/release/download/static_files/pc/images/minetype/UNKNOWN.png)
![file-type](https://csdnimg.cn/release/download/static_files/pc/images/minetype/UNKNOWN.png)
![file-type](https://csdnimg.cn/release/download/static_files/pc/images/minetype/UNKNOWN.png)
![file-type](https://csdnimg.cn/release/download/static_files/pc/images/minetype/UNKNOWN.png)
![file-type](https://csdnimg.cn/release/download/static_files/pc/images/minetype/UNKNOWN.png)
![folder](https://csdnimg.cn/release/downloadcmsfe/public/img/folder.005fa2e5.png)
![folder](https://csdnimg.cn/release/downloadcmsfe/public/img/folder.005fa2e5.png)
![folder](https://csdnimg.cn/release/downloadcmsfe/public/img/folder.005fa2e5.png)
![folder](https://csdnimg.cn/release/downloadcmsfe/public/img/folder.005fa2e5.png)
![folder](https://csdnimg.cn/release/downloadcmsfe/public/img/folder.005fa2e5.png)
![folder](https://csdnimg.cn/release/downloadcmsfe/public/img/folder.005fa2e5.png)
![folder](https://csdnimg.cn/release/downloadcmsfe/public/img/folder.005fa2e5.png)
![folder](https://csdnimg.cn/release/downloadcmsfe/public/img/folder.005fa2e5.png)
![folder](https://csdnimg.cn/release/downloadcmsfe/public/img/folder.005fa2e5.png)
![file-type](https://csdnimg.cn/release/download/static_files/pc/images/minetype/UNKNOWN.png)
![file-type](https://csdnimg.cn/release/download/static_files/pc/images/minetype/UNKNOWN.png)
![folder](https://csdnimg.cn/release/downloadcmsfe/public/img/folder.005fa2e5.png)
![file-type](https://csdnimg.cn/release/download/static_files/pc/images/minetype/UNKNOWN.png)
![folder](https://csdnimg.cn/release/downloadcmsfe/public/img/folder.005fa2e5.png)
![file-type](https://csdnimg.cn/release/download/static_files/pc/images/minetype/UNKNOWN.png)
![file-type](https://csdnimg.cn/release/download/static_files/pc/images/minetype/UNKNOWN.png)
![folder](https://csdnimg.cn/release/downloadcmsfe/public/img/folder.005fa2e5.png)
![file-type](https://csdnimg.cn/release/download/static_files/pc/images/minetype/UNKNOWN.png)
![folder](https://csdnimg.cn/release/downloadcmsfe/public/img/folder.005fa2e5.png)
![file-type](https://csdnimg.cn/release/download/static_files/pc/images/minetype/UNKNOWN.png)
![folder](https://csdnimg.cn/release/downloadcmsfe/public/img/folder.005fa2e5.png)
![folder](https://csdnimg.cn/release/downloadcmsfe/public/img/folder.005fa2e5.png)
![folder](https://csdnimg.cn/release/downloadcmsfe/public/img/folder.005fa2e5.png)
![file-type](https://csdnimg.cn/release/download/static_files/pc/images/minetype/UNKNOWN.png)
![file-type](https://csdnimg.cn/release/download/static_files/pc/images/minetype/UNKNOWN.png)
- 1
![avatar-default](https://csdnimg.cn/release/downloadcmsfe/public/img/lazyLogo2.1882d7f4.png)
![avatar](https://profile-avatar.csdnimg.cn/71a55b92d667478ba9757970f50d9b0b_u013718730.jpg!1)
- 粉丝: 1723
- 资源: 106
我的内容管理 展开
我的资源 快来上传第一个资源
我的收益
登录查看自己的收益我的积分 登录查看自己的积分
我的C币 登录后查看C币余额
我的收藏
我的下载
下载帮助
![voice](https://csdnimg.cn/release/downloadcmsfe/public/img/voice.245cc511.png)
![center-task](https://csdnimg.cn/release/downloadcmsfe/public/img/center-task.c2eda91a.png)
最新资源
- Simulink仿真下的四有源桥电路解耦控制:模型预测控制方法与多种工作模式切换,高精度动态响应及理论推导文件,Simulink仿真实现四有源桥电路解耦控制:模型预测控制下的多模式输出控制,高精度动态
- 基于TypeScript实现的宝霆公共应用API设计源码
- 基于Vue框架的人力资源管理项目Vue2-ihrm设计源码
- PLL锁相环与CMOS模拟集成电路设计教程:初学者快速上手指南,涵盖Verilog模型、Testbench电路与仿真设计文档,初学者必备的PLL锁相环与CMOS模拟集成电路设计资料:涵盖Verilog
- Comsol相场模拟:锂枝晶多核生长的各向异性与温度场效应,Comsol相场模拟:锂枝晶多核生长的各向异性与温度场效应,comsol相场枝晶生长模拟,comsol 锂枝晶生长过程中施加温度场,锂枝晶生
- 基于阿里云SDK与ThinkPHP6的域名分发系统设计源码
- Abaqus静动力学仿真与风振响应分析:光伏支架模态及脉动风模拟研究,Abaqus静动力学仿真与风振响应分析:光伏支架模态及风致振动研究,abaqus静力学动力学仿真分析,风振响应分析,脉动风模拟,光
- 基于Kotlin语言的KotlinFitnessServer运动器械从机服务端设计源码
- 基于COMSOL的锂枝晶生长模型:融合电势场、浓度场与流场,探究电压模式对枝晶形貌的影响,Comsol多场耦合下锂枝晶生长模拟:电势、浓度与流场影响形貌及随机形核研究,comsol 锂枝晶加流动耦合电
- 基于元胞自动机与相场模型的枝晶生长模拟:考虑对流、多物理场与溶质富集的分析研究,利用元胞自动机与LBM模拟枝晶生长:角度自由、物理场多元融合,观察枝晶生长细节与溶质富集动态,C++程序,基于元胞自动机
- 永磁同步电机矢量控制C代码详解:涵盖FOC控制算法、弱磁、母线电流估算及SVPWM技术等多功能实现,永磁同步电机矢量控制C代码详解:涵盖FOC控制算法、弱磁、母线电流估算及SVPWM等技术 这是一个涵
- 基于Vue框架的family_education家教项目设计源码
- 基于Vue2+ElementUI+VueCli的当当书城前端项目设计源码
- 基于Html和Java的桃园中学维修工单与打卡系统设计源码
- 四轮转向汽车Carsim与Simulink联合仿真滑模控制模型详解:涵盖驾驶员模型、二自由度车辆模型、文献及技术支持,四轮转向汽车Carsim与Simulink联合仿真滑模控制模型研究(含文献文档及全
- Simulink模型库:全面解析各类电机模型的应用与搭建方法,基于Simulink技术的多类型电机模型构建与应用,Simulink搭建的各种电机模型 ,电机模型; Simulink; 搭建; 模型模拟
![feedback](https://img-home.csdnimg.cn/images/20220527035711.png)
![feedback-tip](https://img-home.csdnimg.cn/images/20220527035111.png)
![dialog-icon](https://csdnimg.cn/release/downloadcmsfe/public/img/green-success.6a4acb44.png)