一、创建EmployeeMapper接口
public interface EmployeeMapper {
public Employee getEmpById(Integer id);
public Long addEmp(Employee employee);
public boolean updateEmp(Employee employee);
public void deleteEmpById(Integer id);
}
二、创建EmployeeMapper.xml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.atguigu.mybatis.dao.EmployeeMapper">
<!--
namespace:名称空间;指定为接口的全类名
id:唯一标识
resultType:返回值类型
#{id}:从传递过来的参数中取出id值
-->
<!-- public Employee getEmpById(Integer id); -->
<select id="getEmpById" resultType="com.atguigu.mybatis.bean.Employee">
select * from tbl_employee where id = #{id}
</select>
<!-- public Long addEmp(Employee employee); -->
<!-- parameterType可以省略 -->
<!-- 在这里#{lastName}是指取参数employee对象的属性lastName的值 -->
<!--获取自增主键的值:
mysql支持自增主键,自增主键值的获取,mybatis也是利用statement.getGenreatedKeys();
useGeneratedKeys="true";使用自增主键获取主键值策略
keyProperty;指定对应的主键属性,也就是mybatis获取到主键值以后,将这个值封装给javaBean的哪个属性-->
<insert id="addEmp" parameterType="com.atguigu.mybatis.bean.Employee"
useGeneratedKeys="true" keyProperty="id">
insert into tbl_employee(last_name,email,gender)
values(#{lastName},#{email},#{gender})
</insert>
<!-- public boolean updateEmp(Employee employee); -->
<update id="updateEmp">
update tbl_employee
set last_name=#{lastName},email=#{email},gender=#{gender}
where id=#{id}
</update>
<!-- public void deleteEmpById(Integer id); -->
<delete id="deleteEmpById">
delete from tbl_employee where id=#{id}
</delete>
</mapper>
三、测试增删该查
/**
* 1、mybatis允许增删改直接定义以下类型返回值
* Integer、Long、Boolean、void
* 2、我们需要手动提交数据
* sqlSessionFactory.openSession();===》手动提交
* sqlSessionFactory.openSession(true);===》自动提交
* @throws IOException
*/
@Test
public void test01() throws IOException{
String resource = "mybatis-config.xml";
InputStream inputStream = Resources.getResourceAsStream(resource);
SqlSessionFactory sqlSessionFactory = new SqlSessionFactoryBuilder().build(inputStream);
//1、获取到的SqlSession不会自动提交数据
SqlSession openSession = sqlSessionFactory.openSession();
try{
EmployeeMapper mapper = openSession.getMapper(EmployeeMapper.class);
//查询id为1的员工信息
Employee employee = mapper.getEmpById(1);
System.out.println(employee);
//新增员工信息
Employee employee1 = new Employee(null, "jerry4",null, "1");
mapper.addEmp(employee1);
//打印自增主键的值
System.out.println(employee1.getId());
//修改id为1的员工信息
Employee employee2 = new Employee(1, "lizq","[email protected]", "0");
boolean updateEmp = mapper.updateEmp(employee2);
System.out.println(updateEmp);
//删除id为1的员工信息
mapper.deleteEmpById(1);
//2、手动提交数据
openSession.commit();
}finally{
openSession.close();
}
}