mysql 不重复插入数据
REPLACE INTO `db1`.`table1` (`username`,`password`,`salt`,`email`,`regdate`,`regip`) SELECT `uname` as `username`,`password`,`login_salt` as `salt`,`email`,`ctime` as `regdate`,`reg_ip` as `regip` FROM `db2`.`table2`;
REPLACE INTO `db1`.`table1` (`username`,`password`,`salt`,`email`,`regdate`,`regip`) SELECT `uname` as `username`,`password`,`login_salt` as `salt`,`email`,`ctime` as `regdate`,`reg_ip` as `regip` FROM `db2`.`table2`;