(1) Oracle Foundation-User and login

First, the user

· System users

<1> Sys,system

SYS and system are highly privileged users, and SYS is higher than the system permissions. Use SYS to log in must use SYSDBA or Sysoper permissions, and use system to log in directly.

<2> Sysman

Sysman is used to operate Enterprise Manager, administrator-level users.

<3> Scott

Scott is the name of the Oracle founder. As a sample user in Oracle, the default password is Tiger

Second, login

· Sign in to SQL Plus

<1> sign in with the system

Format: [Username/password] [@server] [as SYSDBA | sysoper]

Example: system/botao521 @orcl as Sysdba ( Note: ORCL is the service name or IP address )

<2> logging in with Sys

format: [Username/password] [@server] as Sysdba | sysoper

Example: sys/botao521 @orcl as Sysdba ( Note: login with SYS must use SYSDBA or Sysoper permissions )

P: After login want to change user can use conn [Username/password] [@server] [as SYSDBA | sysoper] Make a replacement user login

· View logged in user

<1> Use the show user command to view currently logged-on users ( Note: TheOracle command does not need to end with a semicolon and the SQL statement must end with a semicolon )

<2> Use the Dba_users data dictionary to view user information. A data dictionary is a table provided by a database that is used to view information about a database.

　　　　 Select username from dba_users View all system users in Oracle

P: You can view table structure using DESC table_name

· Enable Scott Users

　　The Scott user is locked by default and the user-enabled statement is:

Alter user username account unlock , username for any user name

Enable Scott:alter user Scottaccount unlock

P: The statement that locks the user is:alter user username account lock

　　

(1) Oracle Foundation-User and login