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  • Qt数据库查询之事务操作

      在做借书系统的时候,用到了事务操作,不会使用qt中事务操作怎么写,查了一些博客帖子,并不起作用,后来发现,在进行事务成功判断时,出现问题,正确代码如下

     if(QSqlDatabase::database().transaction()){
                        bool res1,res2;
                        query.prepare("update booklist set borrowNum=?,restNum=? where bookId=?");
                        query.bindValue(0,++borrownum);
                        query.bindValue(1,--restnum);
                        query.bindValue(2,bookId);
                        res1=query.exec();
                        //qDebug()<<"insert "<<res1;
    
                        query.prepare("insert into recordlist(bookId,bookName,borrowPeople,borrowTime,backTime,
                                      backState) values(?,?,?,?,?,?)");
                        query.bindValue(0,bookId);
                        query.bindValue(1,bookName);
                        query.bindValue(2,userName);
                        query.bindValue(3,borrowTime);
                        query.bindValue(4,"");
                        query.bindValue(5,0);
                        res2=query.exec();
                         //qDebug()<<query.lastError();
    
                        //qDebug()<<"insert "<<res2;
                        if(res1&&res2){
                            if(!QSqlDatabase::database().commit()){
                                QMessageBox::critical(this,"Error","操作失败,将要回滚");
                                if(!QSqlDatabase::database().rollback()){
                                    QMessageBox::critical(this,"Error","回滚失败");
                                }
                            }else{
                                doShowBackResult();
                                //qDebug()<<"show ";
                            }
                        }else{
                            qDebug()<<query.lastError();
                            QMessageBox::critical(this,"Error","操作失败,将要回滚");
                            if(!QSqlDatabase::database().rollback()){
                                QMessageBox::critical(this,"Error","回滚失败");
                                qDebug()<<QSqlDatabase::database().lastError();
                            }
                        }
    
                    }
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  • 原文地址:https://www.cnblogs.com/tla001/p/6323656.html
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