目录
一、引入POM依赖
<dependency>
<groupId>mysql</groupId>
<artifactId>mysql-connector-java</artifactId>
</dependency>
<dependency>
<groupId>com.baomidou</groupId>
<artifactId>mybatis-plus-boot-starter</artifactId>
<version>3.4.1</version>
</dependency>二、配置文件application.yml
spring:
datasource:
url: jdbc:mysql://172.26.0.296:3306/he?characterEncoding=UTF-8&useUnicode=true&useSSL=false&tinyInt1isBit=false&allowPublicKeyRetrieval=true&serverTimezone=Asia/Shanghai
username: root
password: P0de
driver-class-name: com.mysql.cj.jdbc.Driver
mybatis-plus:
mapper-locations: classpath:mapper/*.xml三、编写表映射实体类
@TableName("sys_user") // 指定表名
public class UserEntity {
private String id;
private String username;
public String id() {
return id;
}
public void setId(String id) {
this.id = id;
}
public String getUsername() {
return username;
}
public void setUsername(String username) {
this.username = username;
}
}四、编写Mapper
简单写个注解sql
public interface TestMapper extends BaseMapper<UserEntity> {
@Select("select id from sys_user limit 1")
String getId();
}五、测试Controller
测试通过：QueryWrapper方式查询 + 注解方式查询。
@RestController
@RequestMapping("/wechat/portal")
public class WechatController {
@Autowired
private TestMapper testMapper;
@GetMapping("/test")
public String getTest() {]
// QueryWrapper方式查询
QueryWrapper<UserEntity> queryWrapper = new QueryWrapper<>();
List<UserEntity> userEntities = testMapper.selectList(queryWrapper);
System.out.println("userEntities --- " + userEntities);
// 注解方式查询
String id = testMapper.getId();
System.out.println("id ---" + id);
return userEntities.toString();
}
}六、启动类
通过@MapperScan指定mapper所在包路径。
@SpringBootApplication
@MapperScan("org.jeecg.modules.mp.mapper") // 指定mapper包路径
public class WxMpDemoApplication {
public static void main(String[] args) {
SpringApplication.run(WxMpDemoApplication.class, args);
}
}OK。