呵。。见笑了。
我以为这个错误大家应该闭着眼睛就知道了
mysql> select * table1 a where exists(select 1 from table1 where userpass=a.userpass and id!=a.id;
ERROR 1064 (42000): You have an error in your SQL syntax; check the manual that
corresponds to your MySQL server version for the right syntax to use near '' at
line 1