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