Re: [Cppcms-users] Bug about transaction in cppdb
Brought to you by:
artyom-beilis
Menu
▾
▴
Re: [Cppcms-users] Bug about transaction in cppdb
|
From: 陈抒 <csf...@gm...> - 2011-10-31 06:22:09
|
It works after using the single update statement. thanks! 陈抒 Best regards http://blog.csdn.net/sheismylife On Mon, Oct 31, 2011 at 9:20 AM, 陈抒 <csf...@gm...> wrote: > Thank you very much. > Your two solutions are same as what I figure out last night? I read the > document of MySQL and find the default isolation level is > repeatable-read.Improve this level or use a single update statement maybe > solve my problem. > > :) > > I am trying now. > > This is not a bug,Sorry for that. > > 陈抒 > Best regards > http://blog.csdn.net/sheismylife > > > On Sun, Oct 30, 2011 at 10:00 PM, Artyom Beilis <art...@ya...>wrote: > >> To be honest I don't know I don't think it is problem with cppdb unless >> you show some specific case that I can reproduce. >> >> I can see >> >> 20071:2011-10-30 11:48:37 GMT; award, notice: obtain a real prize, the >> account_id is:2011.the prize_id is:906326 (default_prize_policy.h:196) >> 20121:2011-10-30 11:48:37 GMT; award, notice: obtain a real prize, the >> account_id is:2011.the prize_id is:906326 (default_prize_policy.h:196) >> >> Which looks exactly the same so it is not inconsistent. >> Maybe innodb allows to do updates if they do not conflict? >> >> I'd suggest to recheck carefully the SQL and other assumptions that >> transaction >> isolation provides (especially in MySQL). >> >> I'd also suggest to do this in one operation like this >> >> stmt = sql << "update event_prize set account_id=? ,award_time=now() >> where prizeId=? and account_id is NULL" << .... >> stmt.exec() >> if(stmt.affected() > 0) >> // awarded >> else >> // not awarder >> >> >> ------------------ >> >> About the isolation level. >> >> Shouldn't >> >> sql << "SET SESSION TRANSACTION ISOLATION Level" << cppdb::exec; >> >> work? >> >> Artyom Beilis >> -------------- >> CppCMS - C++ Web Framework: http://cppcms.sf.net/ >> CppDB - C++ SQL Connectivity: http://cppcms.sf.net/sql/cppdb/ >> >> ------------------------------ >> *From:* 陈抒 <csf...@gm...> >> *To:* cpp...@li... >> *Sent:* Sunday, October 30, 2011 2:05 PM >> *Subject:* Re: [Cppcms-users] Bug about transaction in cppdb >> >> My table is using InnoDB engin. >> >> | event_prize | CREATE TABLE `event_prize` ( >> `prizeId` int(10) unsigned NOT NULL AUTO_INCREMENT, >> `type_id` int(10) unsigned NOT NULL COMMENT '奖品类别Id', >> `promo_id` int(10) unsigned NOT NULL COMMENT '活动Id', >> `account_id` int(10) unsigned DEFAULT NULL COMMENT '获奖人', >> `probility` int(10) unsigned DEFAULT NULL COMMENT >> '1-100之间，进入计算时会除以5000', >> `flag` smallint(5) unsigned DEFAULT '0' COMMENT >> '0：用户可以在任何活动中反复获得;1:只能在一个活动中反复获得；2：每个活动中最多获得一个；3：只能在一个活动中获得一个；4：每个时间段内都确保发出;', >> `status` smallint(5) unsigned DEFAULT '1' COMMENT '1激活 0 冻结', >> `info` varchar(256) DEFAULT NULL COMMENT '保存奖品独特的特征信息', >> `quantity` smallint(5) unsigned DEFAULT '0' COMMENT '一个奖品中标明的数量，比如金额', >> `award_time` datetime DEFAULT NULL, >> PRIMARY KEY (`prizeId`), >> KEY `index_prize_event_promo` (`promo_id`), >> KEY `index_prize_event_type` (`type_id`) >> ) ENGINE=InnoDB AUTO_INCREMENT=1174582 DEFAULT CHARSET=utf8 >> >> 陈抒 >> Best regards >> http://blog.csdn.net/sheismylife >> >> >> On Sun, Oct 30, 2011 at 8:04 PM, 陈抒 <csf...@gm...> wrote: >> >> Hello,Artyom: >> >> I run into one problem,I try to update one record in one MySQL table >> using transaction like so: >> >> static shared_ptr<prize> award(shared_ptr<prize> p,shared_ptr<user> >> user, int promo_id){ >> my_application & app = app_singleton_holder::Instance(); >> cppdb::session session(app.config().master_mysql_uri); >> cppdb::statement stat; >> >> cppdb::transaction guard(session); >> cppdb::result res = session <<"select account_id from event_prize >> where prizeId = ? and account_id is NULL"<< p->id(); >> unsigned int account_id; >> if(res.next() ){ >> stat = session << "update event_prize set account_id=? >> ,award_time=now() where prizeId=?" >> << user->account_id() << p->id(); >> stat.exec(); >> guard.commit(); >> //发送站内短信 >> send_message(p , user , promo_id); >> BOOSTER_NOTICE("award") << "obtain a real prize, the account_id is:" << >> user->account_id() << ".the prize_id is:" << p->id(); >> return p; >> }else{ >> guard.rollback(); >> BOOSTER_NOTICE("award") << "already have got a prize, the account_id >> is:"<< user->account_id() << ".the prize_id is:" << p->id(); >> return create_default_prize(user,promo_id); >> } >> } >> >> Then I write a Java test application using TestNG to test my service >> with 50 threads.But the service updates one record twice.Here is my log: >> >> 20071:2011-10-30 11:48:37 GMT; award, notice: obtain a real prize, the >> account_id is:2011.the prize_id is:906326 (default_prize_policy.h:196) >> 20074:2011-10-30 11:48:37 GMT; award, notice: already have got a prize, >> the account_id is:2011.the prize_id is:906326 (default_prize_policy.h:200) >> 20121:2011-10-30 11:48:37 GMT; award, notice: obtain a real prize, the >> account_id is:2011.the prize_id is:906326 (default_prize_policy.h:196) >> >> Maybe it's a bug.Another question,How to change the transaction >> isolation level for MySQL? >> >> >> 陈抒 >> Best regards >> http://blog.csdn.net/sheismylife >> >> >> >> >> ------------------------------------------------------------------------------ >> Get your Android app more play: Bring it to the BlackBerry PlayBook >> in minutes. BlackBerry App World™ now supports Android™ Apps >> for the BlackBerry® PlayBook™. Discover just how easy and simple >> it is! http://p.sf.net/sfu/android-dev2dev >> >> _______________________________________________ >> Cppcms-users mailing list >> Cpp...@li... >> https://lists.sourceforge.net/lists/listinfo/cppcms-users >> >> >> >> >> ------------------------------------------------------------------------------ >> Get your Android app more play: Bring it to the BlackBerry PlayBook >> in minutes. BlackBerry App World™ now supports Android™ Apps >> for the BlackBerry® PlayBook™. Discover just how easy and simple >> >> it is! http://p.sf.net/sfu/android-dev2dev >> >> _______________________________________________ >> Cppcms-users mailing list >> Cpp...@li... >> https://lists.sourceforge.net/lists/listinfo/cppcms-users >> >> > |
