sqlplus /nolog
conn /as sysdba
conn 用戶名
在DOS環境下，輸入“sqlplus /?”
常用：
sqlplus username/password 如：普通用戶登錄 sqlplus scott/tiger
sqlplus username/password@net_service_name 如: sqlplus scott/tiger@orcl
sqlplus username/password as sysdba 如：sqlplus sys/admin as sysdba
sqlplus myusername/mypassword@ORCL
sqlplus myusername/mypassword@Host/ORCL
sqlplus 用戶名/密碼@IP地址:端口號/實例名
sqlplus /nolog
conn sys/@localhost/orcl as sysdba