MyBatis-Plus通用IService使用

https://www.javadoc.io/static/com.baomidou/mybatis-plus/1.4.0/com/baomidou/framework/service/IService.html

 

自己實戰

凡哥說

UserMapper 按規范是直接對數據庫操作----這個是接口層

UserService 是對數據取出后有業務邏輯的操作 ---這個是去繼承IService類來使用,實際就是封裝了BaseMapper里面的api並且加了點邏輯

 

UserMapper

package com.dao.mapper.test;

import com.baomidou.dynamic.datasource.annotation.DS;
import com.baomidou.mybatisplus.core.mapper.BaseMapper;
import com.dao.entity.User;
import org.apache.ibatis.annotations.Mapper;

@Mapper
@DS("localhostsource")
public interface UserMapper extends BaseMapper<User>{

}

UserService

package com.server.TestService;

import com.baomidou.dynamic.datasource.annotation.DS;
import com.baomidou.mybatisplus.extension.service.IService;
import com.dao.entity.User;


@DS("localhostsource")
public interface UserService extends IService<User> {
    void setvv();
}

 

UserServiceImpl

package com.server.TestService;

import com.baomidou.mybatisplus.core.conditions.query.QueryWrapper;
import com.baomidou.mybatisplus.extension.service.impl.ServiceImpl;
import com.dao.entity.User;
import com.dao.mapper.test.UserMapper;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;
import java.util.List;


@Service
public class UserServiceImpl extends ServiceImpl<UserMapper, User> implements UserService {

    @Autowired
    private UserService userservice;   ------用this.就可以調用方法了 不需要再引入

    @Override
    public void setvv() {
        QueryWrapper<User> queryWrapper = new QueryWrapper<>();
        //模糊查詢
        queryWrapper.like("name", "李四");
        List<User> users = userservice.list(queryWrapper);
        //這里實際用this即可，和上面的寫法是一樣的
//        List<User> users2 = this.list(queryWrapper);
        System.out.println(users);
//        寫入操作
        boolean b = userservice.saveOrUpdateBatch(users);
//        System.out.println(b);

//      調用BaseMapper使用條件構造器--接口類是UserMapper
        this.baseMapper.selectList(queryWrapper);
        this.userservice.getOne(queryWrapper);

        User one = userservice.getOne(queryWrapper, false);
        System.out.println(one);

    }

    }

 

 

常用api方法見:

 

IService API用法

https://blog.csdn.net/qq_39038178/article/details/120612802

https://blog.csdn.net/qq_39038178/article/details/120668991

 

批量插入

public boolean addBatchUserInfo(){
        //多態機制創建一個List集合，創建兩個用戶對象數據，調用add()把用戶對象數據，依次添加到List集合中
        List<UserLoginBean> userList = new ArrayList<>();
        userList.add(new UserLoginBean("list用戶名3","list密碼3"));
        userList.add(new UserLoginBean("list用戶名4","list密碼4"));
        //saveBatch()是mybatis-plus封裝好的，批量添加數據使用，接收集合對象
        //返回boolean類型，true為批量添加成功，反之false批量添加失敗
        return userLoginService.saveBatch(userList);
    }