七、整合MyBatis

1.导入依赖

		<dependency>
            <groupId>org.mybatis.spring.boot</groupId>
            <artifactId>mybatis-spring-boot-starter</artifactId>
            <version>2.1.2</version>
        </dependency>
       <!-- <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-jdbc</artifactId>
        </dependency>
        <dependency>
            <groupId>mysql</groupId>
            <artifactId>mysql-connector-java</artifactId>
            <scope>runtime</scope>
        </dependency>  创建时勾选 JDBC API 和 MYSQL Driver 会自动生成-->

2.配置数据库信息

在properties or yaml 中配置连接数据库

spring.datasource.username=root
spring.datasource.password=123456
spring.datasource.url=jdbc:mysql://localhost:3306/check?serverTimezone=UTC&useUnicode=true&characterEncoding=UTF-8
spring.datasource.driver-class-name=com.mysql.cj.jdbc.Driver

jdbc 8.0 以上需要用com.mysql.cj.jdbc.Driver 且需要配置时区
serverTimezone=UTC 不配置会报错

3.实体类 Student

	private Integer sno;
    private String sname;
    private  Integer sage;
    private String saddress;

有参无参 get set

4.mapper

创建接口 StudentMapper
在接口上加上**@Mapper** 注解表示这是一个mybatis的mapper类或者在main 主类上加上**@MapperScan(xxx)**注解
加上**@Repository** dao层
接口中写方法(CRUD)
```
 List<Student> queryAll();
```

在resource目录下创建mybatis mapper目录创建StudentMapper.xml

<?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.xm.mapper.UserMapper">
    <select id="queryAll" resultType="Student" >
        select * from student;
    </select>
</mapper>

在properties or yaml 中配置 mybatis 的配置信息

mybatis.type-aliases-package=com.xm.pojo
#别名
mybatis.mapper-locations=classpath:mybatis/mapper/*.xml
#绑定mapper

5.controller层

加上**@RestController** controller层

将StudentMapper 自动注入

 @Autowired
    private StudentMapper studentMapper;

实现方法

@GetMapping("/queryUserList")
    public List<Student> queryAll(){
        List<Student> students = studentMapper.queryAll();
        for (Student student : students) {
            System.out.println(student);
        }
        return students;
    }

6.总结

1.在properties yaml中配置数据库信息

2.在接口上加上@Mapper注解 mapper里写方法

3.注意xxxmapper.xml 一定要写在resource下的mybatis/mapper下 namespace一定要改

4.properties yaml中配置绑定mapper

5.controller 层 —> service 层—> dao(mapper)层

步骤

导入依赖
配置文件
mybatis配置
编写sql
service层调用dao
controller 层调用 service层

下一篇学习
SpringBoot详解(六) 从入门到入土 (shiro 邮件)

SpringBoot详解(五) 从入门到入土 (整合Mybatis)