六、mybaits注解实现基本增删改查

环境准备

• 使用第二章的相关表与实体类 userInfo表
• 删除映射文件

Select注解

创建接口，编写查询方法。根据Id查询出一条用户信息

public interface TUserMapper {
    @Select("select * from users_info where uid = #{id}")
    User findTUserById(int id);
}

在mybatis-config.xml中配置引入workerMapper接口

编写测试方法

    @Test
    public void test01(){
        User user = mapper.findTUserById(1);
        System.out.println(user);
    }

insert注解

创建接口，编写插入方法。

@Insert("insert into users_info (uname, uage, uphone) values (#{uname},#{uage},#{uphone});")
int insertUser(User user);

编写测试方法

 @Test
    public void test02(){
        User user = new User();
        user.setUname("hahah");
        user.setUage(55);
        user.setUphone("111111111");
        mapper.insertUser(user);
    }

update注解

创建接口，编写查询方法。

  @Update("update users_info set uname = #{uname} where uid = #{uid};")
    int updateUser(User id);

编写测试方法

    @Test
    public void test03(){
        User user = new User();
        user.setUname("aaaaaaaa");
        user.setUid(6);
        mapper.updateUser(user);

    }

delete注解

创建接口，编写删除方法。

@Delete("delete from users_info where uid = #{uid};")
int deleteUser(int id);

编写测试方法

@Test
public void test04(){
    mapper.deleteUser(6);
}

param注解

若存在多个参数，解决参数对应问题有两种方式

1. sql语句中使用默认参数名，如 Available parameters are [arg1, arg0, param1, param2]

2. 在接口中使用@Param注解

创建接口，编写查询方法。

@Select("select * from users_info where uid = #{id1} and uname = #{name1};")
    User findUserByIdAndName(@Param("id1") int id, @Param("name1") String name);

编写测试方法

@Test
public void test05(){
    mapper.findUserByIdAndName(11,"hahah");
}

全部代码：

package com.yiwu.mapper;
import com.yiwu.pojo.User;
import org.apache.ibatis.annotations.*;

import java.util.List;

public interface TUserMapper {

    @Select("select * from users_info where uid = #{aaaa}")
    User findTUserById(int id);

    @Insert("insert into users_info (uname, uage, uphone) values (#{uname},#{uage},#{uphone});")
    int insertUser(User user);

    @Update("update users_info set uname = #{uname} where uid = #{uid};")
    int updateUser(User id);

    @Delete("delete from users_info where uid = #{uid};")
    int deleteUser(int id);

    @Select("select * from users_info where uid = #{id1} and uname = #{name1};")
    User findUserByIdAndName(@Param("id1") int id, @Param("name1") String name);
}

import com.yiwu.mapper.TUserMapper;
import com.yiwu.pojo.User;
import com.yiwu.utils.MyBatisUtils;
import org.apache.ibatis.session.SqlSession;
import org.junit.After;
import org.junit.Before;
import org.junit.Test;

import java.util.List;

public class TUserTest {
    private TUserMapper mapper;
    private SqlSession sqlSession;

    @Before
    public void init(){
    sqlSession = MyBatisUtils.geSqlSession();
    mapper = sqlSession.getMapper(TUserMapper.class);
}
    @Test
    public void test01(){
        User user = mapper.findTUserById(1);
        System.out.println(user);
    }

    @Test
    public void test02(){
        User user = new User();
        user.setUname("hahah");
        user.setUage(55);
        user.setUphone("111111111");
        mapper.insertUser(user);

    }
    @Test
    public void test03(){
        User user = new User();
        user.setUname("aaaaaaaa");
        user.setUid(6);
        mapper.updateUser(user);
    }

    @Test
    public void test04(){
        mapper.deleteUser(6);
    }
    @Test
    public void test05(){
        mapper.findUserByIdAndName(11,"hahah");
    }
    @After
    public void destory(){
        sqlSession.commit();
        sqlSession.close();
    }
}

---

mybatis基础教程【5小时36讲全套】

重录版-推荐（36讲，无法分享组，点击前往bilibili查看全集）

29注解实现基本查找与插入