第二节-SpringBoot整合Mybatis框架

零、环境搭建

1、创建一张用户表

CREATE TABLE user (
                      id INT PRIMARY KEY AUTO_INCREMENT,
                      name VARCHAR(50) NOT NULL,
                      age INT
);

2、创建对应的实体类

创建一个entity包，创建UserEntity实体类,与user表里的字段一一对应

public class UsetEntity {
    private Integer id;
    private String name;
    private Integer age;

    public UsetEntity(Integer id, String name, Integer age) {
        this.id = id;
        this.name = name;
        this.age = age;
    }

    public void setId(Integer id) {
        this.id = id;
    }

    public void setName(String name) {
        this.name = name;
    }

    public void setAge(Integer age) {
        this.age = age;
    }

    public Integer getId() {
        return id;
    }

    public String getName() {
        return name;
    }

    public Integer getAge() {
        return age;
    }
}

3、在pom.xml中添加依赖

	<!--整合jdbc驱动-->
		<dependency>
			<groupId>org.springframework.boot</groupId>
			<artifactId>spring-boot-starter-jdbc</artifactId>
		</dependency>

		<!--整合mysql模板引擎-->
		<dependency>
			<groupId>mysql</groupId>
			<artifactId>mysql-connector-java</artifactId>
			<version>8.0.33</version>
		</dependency>

		<!--整合mybatis框架-->
		<dependency>
			<groupId>com.baomidou</groupId>
			<artifactId>mybatis-plus-spring-boot3-starter</artifactId>
			<version>3.5.7</version>
		</dependency>

4、配置yml文件

spring:
    datasource:
        driver-class-name: com.mysql.cj.jdbc.Driver
        url: jdbc:mysql://localhost:3306/test?serverTimezone=Asia/Shanghai
        username: root
        password: 123456
    mybatis:
        type-aliases-package: com.zy.entity

一、开始写接口和操作数据库

1、创建service包并创建类UserService，创建mapper包并创建接口UserMapper

创建完后，类UserService和接口UserMapper一定要加上注解@RestController和@Mapper

2、开始写接口

先在UserService写接口,写出通过id查询用户

@RestController
public class UserService {

    @Autowired
    private UserMapper userMapper;
    @RequestMapping("/findByid")
    public User findById(Integer id){
        User user = userMapper.findById(id);
        return user;
    }
}

3、开始在接口UserMapper写mybatis语句

@Mapper
public interface UserMapper {
    @Select("select id as id,name as name,age as age from user where id = #{id}")
    UserEntity findById(@Param("id") Integer id);
}

二、启动程序

输入接口和id为1的参数127.0.0.1:8080/findByid?id=1