《springboot实战》第十一章整合Mybatis plus

古城微笑少年丶 2023-09-26 00:36 20阅读 0赞

## 系列文章目录 ##

[第一章 SpringBoot起步][SpringBoot]  
[第二章 springboot 配置文件、多环境配置、运行优先级][springboot]  
[第三章 springboot 统一日志][springboot 1]  
[第四章 SpringBoot加载静态文件资源][SpringBoot 1]  
[第五章 springboot 拦截器][springboot 2]  
[第六章 实现自定义全局异常处理][Link 1]  
[第七章 springboot 数据库应用][springboot 3]  
[第八章 springboot 整合Druid][springboot _Druid]  
[第九章 springboot 整合MyBatis - xml、注解篇][springboot _MyBatis - xml]  
[第十一章 整合Mybatis plus][_Mybatis plus]  
[第十二章 SpringBoot整合swagger-bootstrap-ui][SpringBoot_swagger-bootstrap-ui]

--------------------

#### 文章目录 ####

*  系列文章目录
 *  前言
 *  1、添加依赖
 *  2、配置数据库连接
 *  3、使用BaseMapper接口
 *   *  3.1、创建表和数据
     *  3.2、定义mapper
     *  3.3、定义service
 *  4、plus分页
 *   *  4.1、添加依赖
     *  4.2、添加配置
     *  4.3、编写分页代码
     *  4.4、分页单元测试类
 *  5、逻辑删除
 *   *  5.1、表新增字段
     *  5.2、实体类
     *  5.3、配置文件
     *  5.4、自动填充审计字段
     *   *  5.4.1、新增字段
         *  5.4.2、实体类修改
         *  5.4.3、实现MetaObjectHandler接口

![在这里插入图片描述][a8cf9b3c27114e969796fec68fd375b1.png]

--------------------

## 前言 ##

MyBatis-Plus (opens new window)（简称 MP）是一个 MyBatis (opens new window)的增强工具，在 MyBatis 的基础上只做增强不做改变，为简化开发、提高效率而生。  
官网：https://baomidou.com/

框架结构：![在这里插入图片描述][5c4ef434d50341c3a4e510720b14f938.png]

## 1、添加依赖 ##

<dependency>
        <groupId>com.baomidou</groupId>
        <artifactId>mybatis-plus-boot-starter</artifactId>
        <version>3.5.2</version>
    </dependency>

## 2、配置数据库连接 ##

spring:
      datasource:
        username: root
        password: root
        url: jdbc:mysql://127.0.0.1:3306/spring
        driver-class-name: com.mysql.cj.jdbc.Driver

## 3、使用BaseMapper接口 ##

### 3.1、创建表和数据 ###

DROP TABLE IF EXISTS user;
    CREATE TABLE user
    (
        id BIGINT(20) NOT NULL COMMENT '主键ID',
        name VARCHAR(30) NULL DEFAULT NULL COMMENT '姓名',
        age INT(11) NULL DEFAULT NULL COMMENT '年龄',
        email VARCHAR(50) NULL DEFAULT NULL COMMENT '邮箱',
        PRIMARY KEY (id)
    );

DELETE FROM user;
    INSERT INTO user (id, name, age, email) VALUES
    (1, 'Jone', 18, 'test1@baomidou.com'),
    (2, 'Jack', 20, 'test2@baomidou.com'),
    (3, 'Tom', 28, 'test3@baomidou.com'),
    (4, 'Sandy', 21, 'test4@baomidou.com'),
    (5, 'Billie', 24, 'test5@baomidou.com');

### 3.2、定义mapper ###

/**
     * 定义mapper类
     */
    public interface UserMapper extends BaseMapper<User>{
        
        @Insert("<script>insert into user(name,age,email) values\n" +
                "        <foreach collection=\"list\" item=\"user\" separator=\",\">\n" +
                "            (#{user.name},#{user.age},#{user.email})\n" +
                "        </foreach>\n" +
                "    </script>")
        int batchInsertUser(List<User> userList);
    }

### 3.3、定义service ###

/**
     * 用户信息服务类
     */
    public interface UserService {
        
        /**
         * 插入用户信息
         * @param user
         * @return
         */
        int insertUser(User user);
    
        /**
         * 批量插入用户信息
         * @param userList
         * @return
         */
        int batchInsertUser(List<User> userList);
    
        /**
         * 更新用户信息
         * @param user
         * @return
         */
        int updateUser(User user);
    
        /**
         * 删除用户信息
         * @param user
         * @return
         */
        int deleteUser(User user);
    
        /**
         * 批量删除用户信息
         * @param ids
         * @return
         */
        int batchDeleteUser(List<Integer> ids);
    
        /**
         * 查询用户信息列表
         * @return
         */
        List<User> selectUser();
    }

@Service
    public class UserServiceImpl implements UserService {
        
        @Autowired
        private UserMapper userMapper;
    
        @Override
        public int insertUser(User user) {
        
            return this.userMapper.insert(user);
        }
    
        @Override
        public int batchInsertUser(List<User> userList) {
        
            return this.userMapper.batchInsertUser(userList);
        }
    
        @Override
        public int updateUser(User user) {
        
            return this.userMapper.updateById(user);
        }
    
        @Override
        public int deleteUser(User user) {
        
            return this.userMapper.deleteById(user);
        }
    
        @Override
        public int batchDeleteUser(List<Integer> ids) {
        
            return this.userMapper.deleteBatchIds(ids);
        }
    
        @Override
        public List<User> selectUser(User user) {
        
            QueryWrapper<User> userQueryWrapper = new QueryWrapper<>();
            //模糊查询
            userQueryWrapper.like(user.getName()!=null,"name",user.getName());
            //精确查询
            userQueryWrapper.eq(user.getEmail()!=null,"email",user.getEmail());
            //范围查询
            userQueryWrapper.between(user.getAge() != null,"age",20,50);
            //排序
            userQueryWrapper.orderByAsc("age");
            return this.userMapper.selectList(userQueryWrapper);        
        }
    }

## 4、plus分页 ##

### 4.1、添加依赖 ###

<dependency>
        <groupId>org.apache.commons</groupId>
        <artifactId>commons-lang3</artifactId>
        <version>3.12.0</version>
    </dependency>

### 4.2、添加配置 ###

@Configuration
    public class MybatisPlusConfig {
        
        @Bean
        public MybatisPlusInterceptor mybatisPlusInterceptor(){
        
            MybatisPlusInterceptor mybatisPlusInterceptor = new MybatisPlusInterceptor();
            mybatisPlusInterceptor.addInnerInterceptor(new PaginationInnerInterceptor(DbType.MYSQL));
            return mybatisPlusInterceptor;
        }
    }

### 4.3、编写分页代码 ###

@Override
    public IPage<User> selectUserPagination(PageDTO<User> pageDTO) {
        
        //传递当前页和页记录数
        IPage<User> iPage = new Page<>(pageDTO.getCurrentPage(),pageDTO.getPageSize(),true);
        QueryWrapper<User> userQueryWrapper = new QueryWrapper<>();
        //查询条件
        User queryUser = pageDTO.getT();
        if(queryUser != null){
        
            //模糊查询
            userQueryWrapper.like(queryUser.getName()!=null,"name",queryUser.getName());
            //精确查询
            userQueryWrapper.eq(queryUser.getEmail()!=null,"email",queryUser.getEmail());
            //范围查询
            userQueryWrapper.between(queryUser.getAge() != null,"age",20,50);
            //排序
            userQueryWrapper.orderByAsc("age");
        }
        return this.page(iPage, userQueryWrapper);
    }

### 4.4、分页单元测试类 ###

@Test
    void testPagination(){
        
        QueryDTO<QueryUserDTO> queryUserDTOQueryDTO = new QueryDTO<>();
    
        queryUserDTOQueryDTO.setCurrentPageNo(1);
        queryUserDTOQueryDTO.setPageSize(10);
    
        QueryUserDTO queryUserDTO = new QueryUserDTO();
        //queryUserDTO.setName("tiger");
        queryUserDTO.setBeginAge(60);
        queryUserDTO.setEndAge(100);
        //queryUserDTO.setEmail("333@qq.com37");
    
        queryUserDTOQueryDTO.setT(queryUserDTO);
    
        System.out.println("############json: " + JSON.toJSONString(queryUserDTOQueryDTO, JSONWriter.Feature.PrettyFormat));
    
    
        System.out.println("############json: " +
                JSON.toJSONString(this.userService.selectUserPagination(queryUserDTOQueryDTO),
                JSONWriter.Feature.PrettyFormat));
    
    }

## 5、逻辑删除 ##

### 5.1、表新增字段 ###

ALTER TABLE `tb_user`
    ADD COLUMN `deleted` INT(1) NULL DEFAULT 0 COMMENT '1代表删除，0代表未删除';

### 5.2、实体类 ###

/**
     * 1 逻辑删除 0 正常
     */
    @TableLogic
    private Integer deleted;

### 5.3、配置文件 ###

mybatis-plus:
      configuration:
        log-impl: org.apache.ibatis.logging.stdout.StdOutImpl #开启sql日志
      global-config:
        db-config:
          logic-delete-value: 1 # 逻辑已删除值(默认为 1)
          logic-not-delete-value: 0 # 逻辑未删除值(默认为 0)

### 5.4、自动填充审计字段 ###

#### 5.4.1、新增字段 ####

![在这里插入图片描述][58de99c45f2549eba7a63e715768e3f1.png]

#### 5.4.2、实体类修改 ####

/**
     * 插入时间
     */
    @TableField(fill = FieldFill.INSERT)
    private LocalDateTime createTime;
    /**
     * 更新时间
     */
    @TableField(fill = FieldFill.UPDATE)
    private LocalDateTime updateTime;

#### 5.4.3、实现MetaObjectHandler接口 ####

/**
     * 元对象处理器
     */
    @Component
    public class MBMetaObjectHandler implements MetaObjectHandler {
        
        @Override
        public void insertFill(MetaObject metaObject) {
        
            this.fillStrategy(metaObject, "createTime",LocalDateTime.now());
        }
    
        @Override
        public void updateFill(MetaObject metaObject) {
        
            this.fillStrategy(metaObject, "updateTime",LocalDateTime.now());
        }
    }

[SpringBoot]: https://blog.csdn.net/s445320/article/details/129921683
[springboot]: https://blog.csdn.net/s445320/article/details/129933138
[springboot 1]: https://blog.csdn.net/s445320/article/details/129949778
[SpringBoot 1]: https://blog.csdn.net/s445320/article/details/129952680
[springboot 2]: https://blog.csdn.net/s445320/article/details/129953402
[Link 1]: https://blog.csdn.net/s445320/article/details/130248527
[springboot 3]: https://blog.csdn.net/s445320/article/details/129958603
[springboot _Druid]: https://blog.csdn.net/s445320/article/details/129989045
[springboot _MyBatis - xml]: https://blog.csdn.net/s445320/article/details/130012383
[_Mybatis plus]: https://blog.csdn.net/s445320/article/details/130130130
[SpringBoot_swagger-bootstrap-ui]: https://blog.csdn.net/s445320/article/details/130419460
[a8cf9b3c27114e969796fec68fd375b1.png]: https://img-blog.csdnimg.cn/a8cf9b3c27114e969796fec68fd375b1.png
[5c4ef434d50341c3a4e510720b14f938.png]: https://img-blog.csdnimg.cn/5c4ef434d50341c3a4e510720b14f938.png
[58de99c45f2549eba7a63e715768e3f1.png]: https://img-blog.csdnimg.cn/58de99c45f2549eba7a63e715768e3f1.png