=CONCATENATE(LOWER(DEC2HEX(RANDBETWEEN(0,4294967295),8)),"-",LOWER(DEC2HEX(RANDBETWEEN(0,65535),4)),"-",LOWER(DEC2HEX(RANDBETWEEN(16384,20479),4)),"-",LOWER(DEC2HEX(RANDBETWEEN(32768,49151),4)),"-",LOWER(DEC2HEX(RANDBETWEEN(0,65535),4)),"-",LOWER(DEC2HEX(RANDBETWEEN(0,4294967295),8)))
原文：http://www.cnblogs.com/leafing/p/6412253.html