用system用户导出,导入时也用system

三个用户名分别为user1,user2,user3

导出:
exp system/passwd file=myexp.dmp log=myexp.log owner=user1,user2,user3

导入:
imp system/passwd file=myexp.dmp log=myimp.log fromuser=user1 touser=user1
imp system/passwd file=myexp.dmp log=myimp.log fromuser=user2 touser=user2
imp system/passwd file=myexp.dmp log=myimp.log fromuser=user3 touser=user3