=CHAR(IF(RANDBETWEEN(1,3)=1,RANDBETWEEN(65,72),(IF(RANDBETWEEN(2,3)=2,RANDBETWEEN(74,78),RANDBETWEEN(80,90)))))&
CHAR(IF(RANDBETWEEN(1,3)=1,RANDBETWEEN(97,107),(IF(RANDBETWEEN(2,3)=2,RANDBETWEEN(109,110),RANDBETWEEN(112,122)))))&
CHAR(IF(RANDBETWEEN(1,3)=1,RANDBETWEEN(97,107),(IF(RANDBETWEEN(2,3)=2,RANDBETWEEN(109,110),RANDBETWEEN(112,122)))))&
CHAR(RANDBETWEEN(50,57))&
CHAR(RANDBETWEEN(50,57))&
CHAR(RANDBETWEEN(50,57))&
CHAR(RANDBETWEEN(50,57))&
CHAR(RANDBETWEEN(50,57))&
CHAR(RANDBETWEEN(50,57))&

CHAR(RANDBETW

EEN(50,57))

第一个&前是大写字母，且不含有歧义的字符
第二个&前是小写字母，且不含有歧义的字符
第三个&前是小写字母，且不含有歧义的字符

第四个&前是数字，且不含有歧义的字符

    本文转自wangheyu1 51CTO博客，原文链接：http://blog.51cto.com/wangheyu1/1972343，如需转载请自行联系原作者