dao層
public interface GoodDao extends BaseMapper<Good> {
}
Service實現類
package mptest.mybatistest.service.impl;
import com.baomidou.mybatisplus.core.conditions.query.QueryWrapper;
import com.baomidou.mybatisplus.core.metadata.IPage;
import com.baomidou.mybatisplus.extension.plugins.pagination.Page;
import com.baomidou.mybatisplus.extension.service.impl.ServiceImpl;
import mptest.mybatistest.mapper.GoodDao;
import mptest.mybatistest.entity.Good;
import mptest.mybatistest.service.IGoodService;
import org.apache.ibatis.annotations.Param;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
@Service
public class GoodServiceImpl extends ServiceImpl<GoodDao,Good> implements IGoodService {
@Autowired
private GoodDao goodDao;
//insert into tb (name) values('nameValue');
public int insert(String name){
Good po=new Good();
po.setName(name);
return goodDao.insert(po);
}
//delete from tb where id=idValue;
public int deleteByID(int id){
return goodDao.deleteById(id);
}
//delete from tb where sex=1 and name='李四';
public int deleteByMap(){
Map<String, Object> columnMap=new HashMap<>();
columnMap.put("sex",1);
columnMap.put("name","李四");
return goodDao.deleteByMap(columnMap);
}
//delete from tb where name="李六";
public int delete(){
return goodDao.delete(new QueryWrapper<Good>().eq("name","李六"));
}
//delete from tb where id in(1,3);
public int deleteBatchIds(){
List list = new ArrayList();
list.add(1);
list.add(3);
return goodDao.deleteBatchIds(list);
}
//update tb set sex=0 where id=6;
public int updateById(){
Good good=new Good();
good.setId(6);
good.setSex(0);
return goodDao.updateById(good);
}
//update tb set sex=1 where name='七七';
public int update1(){
Good good=new Good();
good.setSex(1);
return goodDao.update(good,new QueryWrapper<Good>().eq("name","七七"));
}
//同delete
public Good selectById(){
return goodDao.selectById(6);
}
//同delete
public List selectBatchIds(){
List list = new ArrayList();
list.add(1);
list.add(3);
return goodDao.selectBatchIds(list);
}
//同delete
public List selectByMap(){
Map<String, Object> columnMap=new HashMap<>();
columnMap.put("sex",1);
columnMap.put("name","李四");
return goodDao.selectByMap(columnMap);
}
//如果邏輯非唯一該方法不會自動替您 limit 1 你需要 wrapper.last("limit 1") 設置唯一性。
public Good selectOne(){
return goodDao.selectOne(new QueryWrapper<Good>().eq("name","七七").last("limit 1"));
}
//記錄數
public int selectCount(){
return goodDao.selectCount(new QueryWrapper<Good>().eq("sex","1"));
}
//查全部
public List selectList(){
return goodDao.selectList(new QueryWrapper<Good>());
}
//同上但可自定義增加參數
public List selectMaps(){
List<Map<String,Object>> list=goodDao.selectMaps(new QueryWrapper<Good>());
for(Map m:list){
m.put("zidingyi","aaa");
}
return list;
}
//只返回第一個字段的值
public List selectObjs(){
return goodDao.selectObjs(new QueryWrapper<Good>());
}
//分頁 select * from tb limit 0,2
public void selectPage(){
Page<Good> page = new Page<>(1,2);
IPage iPage= goodDao.selectPage(page,new QueryWrapper<Good>());
}
public void selectMapsPage(){
Page<Good> page = new Page<>(1,2);
IPage iPage= goodDao.selectMapsPage(page,new QueryWrapper<Good>());
}
}