MySQL 临时变量取值三例

例子1：常规用法

DECLARE iSystemTypeId INT;
set iSystemTypeId  = NULL;
select SystemTypeId into iSystemTypeId from B_SystemType  where os = Aos;

 

例子2：trigger中用的多
DECLARE lockTime datetime;
set  lockTime=(select lockTime from ccmUsers where name=myuser);

 

例子3：临时变量用户
set @mysum=0;                                  
select @mysum:=COUNT(*) from mendpinfo where ipaddr = rvIpaddr;

原文地址：http://blog.csdn.net/panpanxj/article/details/2729791