Example: Suppose you want to know when the MySql packages was last installed or upgraded.
The syntax should be:
[root@Hostxyz ~]# rpm -qa --last | grep -i mysql
MySQL-client-5.6.5_m8-1.rhel5 Fri 13 Jul 2012 02:35:01 AM PDT
MySQL-server-5.6.5_m8-1.rhel5 Fri 13 Jul 2012 02:34:44 AM PDT
php54-mysql-5.4.0-1.el5 Fri 13 Jul 2012 01:17:21 AM PDT