MyBatisPlus快速入门
1.1 入门流程分析
SpringBoot 整合 MyBatis-Plus，并实现根据Id查询功能。
- 数据库环境准备（这里我用的是docker部署mysql8.0）
- 创建SpringBoot工程，引入MyBatisPlus场景依赖
- 在yml中编写DataSource相关配置
- 编写mapper
- 测试
1.2 数据库环境准备
SET NAMES utf8mb4;
SET FOREIGN_KEY_CHECKS = 0;
-- ----------------------------
-- Table structure for tb_user 没有给自增
-- ----------------------------
DROP TABLE IF EXISTS `tb_user`;
CREATE TABLE `tb_user` (
`id` bigint(20) NOT NULL AUTO_INCREMENT,
`user_name` varchar(255) DEFAULT NULL,
`password` varchar(255) DEFAULT NULL,
`name` varchar(255) DEFAULT NULL,
`age` int(11) DEFAULT NULL,
`email` varchar(255) DEFAULT NULL,
PRIMARY KEY (`id`)
) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4;
-- ----------------------------
-- Records of tb_user
-- ----------------------------
BEGIN;
INSERT INTO `tb_user` VALUES (1, '赵一伤', '123456', 'zys', 19, 'zys@itcast.cn');
INSERT INTO `tb_user` VALUES (2, '钱二败', '123456', 'qes', 18, 'qes@itcast.cn');
INSERT INTO `tb_user` VALUES (3, '孙三毁', '123456', 'ssh', 20, 'ssh@itcast.cn');
INSERT INTO `tb_user` VALUES (4, '李四摧', '123456', 'lsc', 20, 'lsc@itcast.cn');
INSERT INTO `tb_user` VALUES (5, '周五输', '123456', 'zws', 20, 'zws@itcast.cn');
INSERT INTO `tb_user` VALUES (6, '吴六破', '123456', 'wlp', 21, 'wlp@itcast.cn');
INSERT INTO `tb_user` VALUES (7, '郑七灭', '123456', 'zqm', 22, 'zqm@itcast.cn');
INSERT INTO `tb_user` VALUES (8, '王八衰', '123456', 'wbs', 22, 'wbs@itcast.cn');
INSERT INTO `tb_user` VALUES (9, '张无忌', '123456', 'zwj', 25, 'zwj@itcast.cn');
INSERT INTO `tb_user` VALUES (10, '赵敏', '123456', 'zm', 26, 'zm@itcast.cn');
INSERT INTO `tb_user` VALUES (11, '赵二伤', '123456', 'zes', 25, 'zes@itcast.cn');
INSERT INTO `tb_user` VALUES (12, '赵三伤', '123456', 'zss1', 28, 'zss1@itcast.cn');
INSERT INTO `tb_user` VALUES (13, '赵四伤', '123456', 'zss2', 29, 'zss2@itcast.cn');
INSERT INTO `tb_user` VALUES (14, '赵五伤', '123456', 'zws', 39, 'zws@itcast.cn');
INSERT INTO `tb_user` VALUES (15, '赵六伤', '123456', 'zls', 29, 'zls@itcast.cn');
INSERT INTO `tb_user` VALUES (16, '赵七伤', '123456', 'zqs', 39, 'zqs@itcast.cn');
COMMIT;
SET FOREIGN_KEY_CHECKS = 1;
1.3 创建工程，引入场景依赖
<parent>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-parent</artifactId>
<version>2.3.10.RELEASE</version>
<relativePath/> <!-- lookup parent from repository -->
</parent>
<properties>
<java.version>1.8</java.version>
</properties>
<dependencies>
<!-- mysql 驱动-->
<dependency>
<groupId>mysql</groupId>
<artifactId>mysql-connector-java</artifactId>
</dependency>
<!-- lombok ,自动生成get,Set 方法-->
<dependency>
<groupId>org.projectlombok</groupId>
<artifactId>lombok</artifactId>
<optional>true</optional>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-test</artifactId>
<scope>test</scope>
</dependency>
<!--mybatisplus起步依赖-->
<dependency>
<groupId>com.baomidou</groupId>
<artifactId>mybatis-plus-boot-starter</artifactId>
<version>3.4.2</version>
</dependency>
</dependencies>
1.4 编写DataSource相关配置
#datasource
spring:
datasource:
url: jdbc:mysql://localhost:3306/mp?useUnicode=true&characterEncoding=UTF-8&serverTimezone=UTC
username: root #自行设置用户名和密码，并且注意上面3306/mp，这里mp得替换成自己创建的数据库
password: root
driver-class-name: com.mysql.jdbc.Driver
#mybatis-plus配置控制台打印完整带参数SQL语句
mybatis-plus:
configuration:
log-impl: org.apache.ibatis.logging.stdout.StdOutImpl
1.5 编码
实体类
package com.itheima.sh.pojo;
import com.baomidou.mybatisplus.annotation.TableName;
import lombok.Data;
/**
* @Description:
* @Version: V1.0
*/
@TableName("tb_user") // 指定表名，注意如果数据库的表名和实体类一致时可以省略
@Data
@NoArgsConstructor
@AllArgsConstructor
@Builder
public class User {
private Long id;
private String userName;
private String password;
private String name;
private Integer age;
private String email;
}
编写mapper
package com.itheima.sh.mapper;
import com.baomidou.mybatisplus.core.mapper.BaseMapper;
import com.itheima.sh.pojo.User;
/**
* 使用mp定义Mapper，需要让Mapper接口继承 BaseMapper接口。
*/
public interface UserMapper extends BaseMapper<User> {
}
启动类增加@MapperScan注解
package com.itheima.sh;
import org.mybatis.spring.annotation.MapperScan;
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
@SpringBootApplication
@MapperScan("com.itheima.sh.mapper")
public class MpApplication {
public static void main(String[] args) {
SpringApplication.run(MpApplication.class, args);
}
}
1.6 测试
package com.itheima.sh;
import com.itheima.sh.mapper.UserMapper;
import com.itheima.sh.pojo.User;
import org.junit.jupiter.api.Test;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.boot.test.context.SpringBootTest;
@SpringBootTest
public class UserMapperTest {
@Autowired
private UserMapper userMapper;
/**
* 根据id查询
*/
@Test
public void testSelectById() {
User user = userMapper.selectById(1L);
System.out.println(user);
}
}
测试结果：
