SpringBoot（六）SpringBoot整合MyBatis/异步-定时-邮件任务

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学习视频链接，以示尊重：https://www.bilibili.com/video/BV1PE411i7CV?p=51

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一、SpringBoot整合MyBatis

1、导入 MyBatis 所需要的依赖：

<!-- https://mvnrepository.com/artifact/org.mybatis.spring.boot/mybatis-spring-boot-starter -->
<dependency>
    <groupId>org.mybatis.spring.boot</groupId>
    <artifactId>mybatis-spring-boot-starter</artifactId>
    <version>2.1.3</version>
</dependency>

2、配置数据库连接信息（和上一节所学SpringBoot继承Druid所配置信息相同）

3、创建实体类：

@Data
@NoArgsConstructor
@AllArgsConstructor
public class Department {
   

    private Integer id;
    private String departmentName;

}

4、创建mapper目录以及对应的 Mapper 接口：

//@Mapper : 表示本类是一个 MyBatis 的 Mapper
@Mapper
@Repository
public interface DepartmentMapper {
   

    // 获取所有部门信息
    List<Department> getDepartments();

    // 通过id获得部门
    Department getDepartment(Integer id);

}

5、对应地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..xingyu.springbootlearn.mapper.DepartmentMapper">

    <select id="getDepartments" resultType="Department">
       select * from department;
    </select>

    <select id="getDepartment" resultType="Department" parameterType="int">
       select * from department where id = #{id};
    </select>

</mapper>

或者直接使用注解：

@Mapper
@Repository
public interface DepartmentMapper {
   

    // 获取所有部门信息
    @Select("select * from department")
    List<Department> getDepartments();

    // 通过id获得部门
    @Select("select * from department where id = #{id}")
    Department getDepartment(@Param