Spring Boot框架 - 数据访问 - 整合Mybatis

一、新建Spring Boot项目

     注意：创建的时候勾选Mybatis依赖，pom文件如下

<dependency>
    <groupId>org.mybatis.spring.boot</groupId>
    <artifactId>mybatis-spring-boot-starter</artifactId>
     <version>2.1.1</version>
</dependency>

二、配置文件application.properties中配置数据库信息

三、创建两个表（Employee，Department）

四、创建JavaBean 用来封装表的数据

五、使用mybatis对数据库进行操作

• 配置文件方式
  • 在resources目录下新建目录：

• • mybatis-config.xml  内容如下

    <?xml version="1.0" encoding="UTF-8" ?>
    <!DOCTYPE configuration
            PUBLIC "-//mybatis.org//DTD Config 3.0//EN"
            "http://mybatis.org/dtd/mybatis-3-config.dtd">
    <configuration>
    
    </configuration>

  • EmployeeMapper.xml 内容如下

    <?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">
    
    <!--将EmployeeMapper的全类名（右键复制相对路径）复制出来，放在namespace里面-->
    <mapper namespace="com.demo.springboot.mapper.EmployeeMapper">
    
        <!--将接口的方法配置到映射文件中
        id="方法名"
        resultType="返回值类型Employee的全类名"-->
        <select id="getEmpById" resultType="com.demo.springboot.bean.Employee">
            select * from Employee where id=#{id};
        </select>
    </mapper>

  • 将EmployeeMapper接口的方法配置在映射文件EmployeeMapper.xml中 

  • 在application.properties 中添加配置

    #mybatis配置
    mybatis.config-location=classpath:mybatis/mybatis-config.xml
    mybatis.mapper-locations=classpath:mybatis/mapper/*.xml

  • 运行后测试（同下面的注解版 “***测试：新增一个Controller.DeptController”）　　　
• 注解版方式
  • 创建包：mapper
  • 在包下添加一个接口：DepartmentMapper

    /**
     * 指定这是一个操作数据库的mapper
     */
    @Mapper
    public interface DepartmentMapper {
    
        @Select("select * from Department where id=#{id}")
        public Department getDeptById(Integer id);
    
        @Delete("delete from Department where id=#{id}")
        public int deleteDeptById(Integer id);
    
        @Insert("insert into Department(departmentName) values=(#{departmentName})")
        public int insertDept(Department department);
    
        @Update("update Department set departmentName=#{departmentName} where id=#{id}")
        public int updateDept(Department department);
    }

  • ***测试：新增一个Controller.DeptController

    @RestController
    public class DeptController {
    
        @Autowired
        DepartmentMapper departmentMapper;
    
       //查询，带入浏览器中的参数id
        @GetMapping("dept/{id}")
        public Department getDepartment(@PathVariable("id") Integer id){
            return departmentMapper.getDeptById(id);
        }
    
       //插入
        @GetMapping("dept/add")
        public Department addDepartment(Department department){
            departmentMapper.insertDept(department);
            return department;
        }
    }

  • 测试结果：

    • 测试查询：在浏览器输入地址 http://localhost:8080/dept/1

    • 测试插入：http://localhost:8080/dept/add?departmentName=%E6%8A%80%E6%9C%AF%E9%83%A8&empNum=13 查看数据库，新增数据成功