SpringBoot 简单使用mybatis

Posted 2021-07-17 冷血～多好

1.导入 MyBatis 所需要的依赖

  <!--mybatis-spring-boot-starter:整合-->
        <dependency>
            <groupId>org.mybatis.spring.boot</groupId>
            <artifactId>mybatis-spring-boot-starter</artifactId>
            <version>2.1.4</version>
        </dependency>

          <dependency>
            <groupId>mysql</groupId>
            <artifactId>mysql-connector-java</artifactId>
            <version>5.1.47</version>
            <scope>runtime</scope>
        </dependency>
        
          <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-web</artifactId>
        </dependency>

2.配置数据库连接信息(application.properties)

spring.datasource.username=root
spring.datasource.password=123
spring.datasource.url=jdbc:mysql://localhost:3306/mybatis?serverTimezone=UTC&useUnicode=true&characterEncoding=utf-8
spring.datasource.driver-class-name=com.mysql.jdbc.Driver

测试：

@SpringBootTest
class Springboot05MybatisApplicationTests {


    @Autowired
    DataSource dataSource;

    @Test
    void contextLoads() throws SQLException {

        System.out.println(dataSource.getClass());
        System.out.println(dataSource.getConnection());

    }

}

打印出：class com.zaxxer.hikari.HikariDataSource
             HikariProxyConnection@1172943149 wrapping com.mysql.jdbc.JDBC4Connection@3dc95b8b

说明配置完成

 

3.然后进行crud操作：

 

先编写一个实体类：（注意这里使用了lombok插件)

import lombok.AllArgsConstructor;
import lombok.Data;
import lombok.NoArgsConstructor;
import org.springframework.beans.factory.annotation.Autowired;

@Data
@AllArgsConstructor
@NoArgsConstructor
public class User {

    private int id;
    private String name;
    private String pwd;



}

创建mapper目录以及对应的 Mapper 接口

import com.chen.pojo.User;
import org.apache.ibatis.annotations.Mapper;
import org.springframework.stereotype.Repository;

import java.util.List;


//这个注解表示了这时一个mybatis的mapper类：Dao
@Mapper

@Repository
public interface UserMapper {


    List<User> queryUserList();

    User queryUserById(int id);

    int addUSer(User user);

    int updateUser(User user);

    int deleteUser(int id);

}

对应的Mapper映射文件

<?xml version="1.0" encoding="UTF-8" ?>
<!DOCTYPE mapper
        PUBLIC "-//mybatis.org//DTD Mapper 3.0//EN"
        "http://mybatis.org/dtd/mybatis-3-mapper.dtd">
<mapper namespace="com.chen.mapper.UserMapper">


    <!--select查询语句-->
    <!--id为方法名,resultType为结果返回类型-->
    <select id="queryUserList" resultType="User">
    select * from mybatis.user;
  </select>




    <!--通过id进行select查询语句，parameterType为传参类型，resultType为结果返回类型-->
    <select id="queryUserById"  parameterType="int" resultType="User">
      select *from mybatis.user where id=#{id};
   </select>


    <!--插入语句，对象中的属性，可以直接取出来-->
    <insert id="addUSer" parameterType="User" >
          insert into mybatis.user(name,pwd) values (#{name},#{pwd});
      </insert>





    <!--更改用户语句-->
    <insert id="updateUser" parameterType="User" >
        update mybatis.user set name =#{name},pwd=#{pwd} where id=#{id};
      </insert>



    <!--删除用户-->
    <delete id="deleteUser" parameterType="int">
        delete from mybatis.user where id=#{id};
    </delete>


</mapper>

 

编写用户的UserController 进行测试！

import com.chen.mapper.UserMapper;
import com.chen.pojo.User;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.RestController;

import java.util.List;

@RestController
public class UserController {

    @Autowired
    private UserMapper userMapper;

    @GetMapping("/queryUserList")
    public List<User> queryUserList(){
        List<User> userList=userMapper.queryUserList();
        for(User user:userList){
            System.out.println(user);
        }
        return  userList;
    }

    //添加一个用户
    @GetMapping("/addUser")
    public String addUser(){
        int n=userMapper.addUSer(new User(5,"阿毛","4566977"));
        return String.valueOf(n);
    }

    //修改一个用户
    @GetMapping("/updateUser")
    public String updateUser(){
        int n=userMapper.updateUser(new User(5,"阿毛","4566977"));
        return String.valueOf(n);
    }

    //删除一个用户
    @GetMapping("/deleteUser")
    public String deleteUser(){
        int n=userMapper.deleteUser(18);
        return String.valueOf(n);
    }

}

 

最后创建该实体类数据库：mybatis

DROP TABLE IF EXISTS `user`;
CREATE TABLE `user`  (
  `id` int(11) NOT NULL AUTO_INCREMENT,
  `name` varchar(25) CHARACTER SET gbk COLLATE gbk_chinese_ci NULL DEFAULT NULL,
  `pwd` varchar(25) CHARACTER SET gbk COLLATE gbk_chinese_ci NULL DEFAULT NULL,
  PRIMARY KEY (`id`) USING BTREE
) ENGINE = InnoDB AUTO_INCREMENT = 18 CHARACTER SET = gbk COLLATE = gbk_chinese_ci ROW_FORMAT = Compact;

-- ----------------------------
-- Records of user
-- ----------------------------
INSERT INTO `user` VALUES (3, '小黑', '789');
INSERT INTO `user` VALUES (4, '可可2', '151');
INSERT INTO `user` VALUES (5, '阿毛', '4566977');
INSERT INTO `user` VALUES (6, '小明', 'cafa1414f');
INSERT INTO `user` VALUES (7, '嘻嘻3', '101112');
INSERT INTO `user` VALUES (8, '很爱很爱你', '101112');
INSERT INTO `user` VALUES (9, '小霞', '159');
INSERT INTO `user` VALUES (10, '嘻嘻5', '101112');
INSERT INTO `user` VALUES (11, '陈锦贤', 'dad45');
INSERT INTO `user` VALUES (12, '陈锦贤2', 'd2ad45');
INSERT INTO `user` VALUES (13, '小明', '123456');
INSERT INTO `user` VALUES (14, '小明2', '456');
INSERT INTO `user` VALUES (17, '阿毛', '4566977');

SET FOREIGN_KEY_CHECKS = 1;

然后就可以启动项目进行测试了：

浏览器打开：

http://localhost:8080/queryUserList

其它的删除，添加，修改也是如此！