MyBatis-Plus 光速入门-一一网

简介

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。
官方文档

快速入门

建库建表，创项目，导入依赖，写配置文件，连接数据库
写实体类（pojo），
编写继承自BaseMapper的Mapper接口
无需写sql语句，直接CRUD

体验一把（创建的springboot项目）

导入依赖

<dependencies>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-jdbc</artifactId>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-web</artifactId>
        </dependency>

        <dependency>
            <groupId>mysql</groupId>
            <artifactId>mysql-connector-java</artifactId>
            <version>8.0.22</version>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-test</artifactId>
            <scope>test</scope>
        </dependency>
        <dependency>
            <groupId>org.projectlombok</groupId>
            <artifactId>lombok</artifactId>
        </dependency>
        <dependency>
            <groupId>com.baomidou</groupId>
            <artifactId>mybatis-plus-boot-starter</artifactId>
            <version>3.4.2</version>
        </dependency>

    </dependencies>
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pojo

@Data
@AllArgsConstructor
@NoArgsConstructor
@Accessors(chain = true)//开启链式
public class User {
    @TableId(type = IdType.AUTO)//ID_WORKER已过时，作者建议使用ASSIGN_ID。AUTO自增
    private Long id;
    private String name;
    private Integer age;
    private String email;
}
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Mapper接口

@Mapper
@Repository//持久层注解
public interface UserMapper extends BaseMapper<User> {
    //所有CRUD已经完成
    //Mapper 继承该接口后，无需编写 mapper.xml 文件，即可获得CRUD功能
}
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配置文件（application.yaml）

spring:
  datasource:
    username: root
    password: 123456
    url: jdbc:mysql://localhost:3306/mybatis-plus?useUnicode=true&characterEncoding=utf8&useSSL=true&serverTimezone=Asia/Shanghai
    driver-class-name: com.mysql.cj.jdbc.Driver
# 配置日志
mybatis-plus:
  configuration:
    log-impl: org.apache.ibatis.logging.stdout.StdOutImpl  # 用什么日志就要导入相应的依赖
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Test类

@SpringBootTest
class MybatisPlusFastStartApplicationTests {
    @Autowired
    private UserMapper userMapper;
    @Test
    void contextLoads() {                         //参数是Wrapper
        List<User> list = userMapper.selectList(null);
        System.out.println(Arrays.toString(list.toArray()));
    }
}

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