Mybatis增刪改查的實現
阿新 • • 發佈:2022-01-17
查
1,編寫介面方法
public interface userMapper {
//根據ID查詢使用者
User getUserByID(int id);
}
2,編寫Mapper中sql語句
<select id="getUserByID" resultType="com.Google.pojo.User" parameterType="int">
select * from user where id= #{id}
</select>
3,實現
public void getUserByID(){ SqlSession sqlSession = sqlSessionFactory.getsqlSession(); userMapper mapper = sqlSession.getMapper(userMapper.class); User userByID = mapper.getUserByID(1); System.out.println(userByID); sqlSession.close(); }
增
1.編寫介面中的方法
int addUser (User user);
2.編寫Mapper中的sql語句
<!--增加使用者-->
<insert id="addUser" parameterType="com.Google.pojo.User">
insert into user (id,name,pwd) value (#{id},#{name},#{pwd})
</insert>
3.實現
public void addUser (){ SqlSession sqlSession = sqlSessionFactory.getsqlSession(); userMapper mapper = sqlSession.getMapper(userMapper.class); int nums = mapper.addUser(new User(4, "秋君", "123123")); if(nums>0){ sqlSession.commit();//提交事務(增刪改都需要提交事務) } }
刪
1.編寫介面中的方法
int deleteUser (int id);
2.編寫Mapper中的sql語句
<!--刪除使用者-->
<delete id="deleteUser" parameterType="int">
delete from user where id=#{id}
</delete>
3.實現
public void deleteUser(){ SqlSession sqlSession = sqlSessionFactory.getsqlSession(); userMapper mapper = sqlSession.getMapper(userMapper.class); int nums = mapper.deleteUser(4); if(nums>0){ sqlSession.commit(); } sqlSession.close(); }
改
1.編寫介面中的方法
int updateUser (User user);
2.編寫Mapper中的sql語句
<!--修改使用者-->
<update id="updateUser" parameterType="com.Google.pojo.User">
update user
set name=#{name},pwd=#{pwd}
where id=#{id};
</update>
3.實現
public void updateUser(){
SqlSession sqlSession = sqlSessionFactory.getsqlSession();
userMapper mapper = sqlSession.getMapper(userMapper.class);
int nums = mapper.updateUser(new User(4, "小羅", "123123123"));
if(nums>0){
sqlSession.commit();
}
}