Mybatis 操作续集(结合上文)

当我们增加一个数据之后,如果我们想要获取它的 Id 进行别的操作,我们该如何获取 Id 呢?

用那个@Options

package com.example.mybatisdemo.mapper;

import com.example.mybatisdemo.model.UserInfo;
import org.apache.ibatis.annotations.*;

import java.util.List;

@Mapper
public interface UserInfoMapper {
   
    @Options(useGeneratedKeys = true,keyProperty = "id")
    @Insert(" insert into userinfo(username,password,age,gender,phone) " +
            "value(#{username},#{password},#{age},#{gender},#{phone})")
    Integer insert(UserInfo userInfo);

}

然后log.info 里面加上userinfo.getId

package com.example.mybatisdemo.mapper;

import com.example.mybatisdemo.model.UserInfo;
import lombok.extern.slf4j.Slf4j;
import org.junit.jupiter.api.AfterEach;
import org.junit.jupiter.api.BeforeEach;
import org.junit.jupiter.api.Test;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.boot.test.context.SpringBootTest;

import java.util.List;

import static org.junit.jupiter.api.Assertions.*;

@Slf4j
@SpringBootTest
class UserInfoMapperTest {
    @Autowired
    private UserInfoMapper userInfoMapper;
   
    @Test
    void insert() {
        UserInfo userInfo = new UserInfo();
        userInfo.setUsername("zhaoliu");
        userInfo.setPassword("123");
        userInfo.setAge(45);
        userInfo.setGender(0);
        userInfo.setPhone("1775423");

        Integer result = userInfoMapper.insert(userInfo);
        log.info("insert 方法,执行结果:{},自增ID:{}",result,userInfo.getId());
    }
}

这样就能在日志中拿到这个Id了

我们在 Mysql 中看到确实是8

接下来,对 insert 的参数如何进行重命名呢?

(就是username和password这些属性前面都加上重命名之后的名字,比如重命名为userinfo,就写为userinfo.username,还有@Param()括号里面写下要改的名字)

package com.example.mybatisdemo.mapper;

import com.example.mybatisdemo.model.UserInfo;
import org.apache.ibatis.annotations.*;

import java.util.List;

@Mapper
public interface UserInfoMapper {
    
    @Options(useGeneratedKeys = true,keyProperty = "id")
    @Insert(" insert into userinfo(username,password,age,gender,phone) " +
            "value(#{username},#{password},#{age},#{gender},#{phone})")
    Integer insert(UserInfo userInfo);

    @Options(useGeneratedKeys = true,keyProperty = "id")
    @Insert(" insert into userinfo(username,password,age,gender,phone) " +
            "value(#{userinfo.username},#{userinfo.password},#{userinfo.age},#{userinfo.gender},#{userinfo.phone})")
    Integer insert2(@Param("userinfo") UserInfo userInfo);


}

然后依旧右键generate,test,勾选,ok

package com.example.mybatisdemo.mapper;

import com.example.mybatisdemo.model.UserInfo;
import lombok.extern.slf4j.Slf4j;
import org.junit.jupiter.api.AfterEach;
import org.junit.jupiter.api.BeforeEach;
import org.junit.jupiter.api.Test;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.boot.test.context.SpringBootTest;

import java.util.List;

import static org.junit.jupiter.api.Assertions.*;

@Slf4j
@SpringBootTest
class UserInfoMapperTest {
    @Autowired
    private UserInfoMapper userInfoMapper;
  
    @Test
    void insert2() {
        UserInfo userInfo = new UserInfo();
        userInfo.setUsername("zhaoliu");
        userInfo.setPassword("123");
        userInfo.setAge(45);
        userInfo.setGender(0);
        userInfo.setPhone("1775423");

        Integer result = userInfoMapper.insert(userInfo);
        log.info("insert 方法,执行结果:{},自增ID:{}",result,userInfo.getId());
    }
}

这样就能成功了

接下来是删除操作

package com.example.mybatisdemo.mapper;

import com.example.mybatisdemo.model.UserInfo;
import org.apache.ibatis.annotations.*;

import java.util.List;

@Mapper
public interface UserInfoMapper {
   
    @Delete("delete from userinfo where id=#{id}")
    Integer delete(Integer id);//想根据什么条件删除,括号就传什么条件


}

右键,generate,test,勾选,ok

package com.example.mybatisdemo.mapper;

import com.example.mybatisdemo.model.UserInfo;
import lombok.extern.slf4j.Slf4j;
import org.junit.jupiter.api.AfterEach;
import org.junit.jupiter.api.BeforeEach;
import org.junit.jupiter.api.Test;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.boot.test.context.SpringBootTest;

import java.util.List;

import static org.junit.jupiter.api.Assertions.*;

@Slf4j
@SpringBootTest
class UserInfoMapperTest {
    @Autowired
    private UserInfoMapper userInfoMapper;
    
    @Test
    void delete() {
        userInfoMapper.delete(9);
    }
}

这样就运行成功了

我们就会发现Id为 9 的数据被删除了

上面的 select 是 delete之前查找的,下面的是 delete 之后查找的

接下来是"改"操作

package com.example.mybatisdemo.mapper;

import com.example.mybatisdemo.model.UserInfo;
import org.apache.ibatis.annotations.*;

import java.util.List;

@Mapper
public interface UserInfoMapper {
    
    @Update("update userinfo set age=#{age} where id=#{id}")
    Integer update(UserInfo userInfo);

}

右键,generate,test,勾选,OK

package com.example.mybatisdemo.mapper;

import com.example.mybatisdemo.model.UserInfo;
import lombok.extern.slf4j.Slf4j;
import org.junit.jupiter.api.AfterEach;
import org.junit.jupiter.api.BeforeEach;
import org.junit.jupiter.api.Test;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.boot.test.context.SpringBootTest;

import java.util.List;

import static org.junit.jupiter.api.Assertions.*;

@Slf4j
@SpringBootTest
class UserInfoMapperTest {
    @Autowired
    private UserInfoMapper userInfoMapper;
    
    @Test
    void update() {
        UserInfo userInfo = new UserInfo();
        userInfo.setAge(78);
        userInfo.setId(7);
        Integer result=userInfoMapper.update(userInfo);//受影响的行数,也就是一般Mysql执行一段语句之后的最后一行
        if (result>0){//如果受影响的行数大于0,说明执行成功了
            log.info("数据修改成功");
        }
    }
}