关于PHP并发的有关问题
关于PHP并发的问题
MYSQL是不是有防止并发的机制，可以解释听听吗。
例如库存只有1，两个用户同时购买减1后，会是负数了。。
但不用PHP执行，让SQL来完成这个操作 a=a-1 ... where a>0 就可以解决了吗。
这方面的知识比较缺乏，不知道有没有前辈的帖子可以查看一下，谢谢
------解决方案--------------------
http://ourmysql.com/archives/857
http://www.orczhou.com/index.php/2010/06/mysql-innodb-source-code-sync-1/
http://www.cnblogs.com/perfectdesign/archive/2009/12/05/1617508.html
------解决方案--------------------
MYSQL 有并发机制，可以防止不同用户间的访问冲突
让SQL来完成这个操作 a=a-1 ... where a>0 就可以防止存量为负的现象存在
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