mysql> update test set create_time=concat('2013-10-01 ', floor(10+rand()*10),':',floor(10+rand()*49),':',floor(10+rand()*49)) where create_time='0000-00-00 00:00:00';
Query OK, 1 row affected
Rows matched: 1 Changed: 1 Warnings: 0
原文：http://blog.csdn.net/benjamin_whx/article/details/37517017