在Ubuntu 16.04中安装sqlplus后，执行时要求输入用户名密码但无凭据

Hey there, let's work through this sqlplus login snag you're hitting on Ubuntu 16.04!

First off, sqlplus relies on Oracle database user credentials to log in—this is expected behavior. If you've only installed the sqlplus client but haven't set up or connected to an Oracle database instance yet, here's how to get past this:

• Use built-in admin accounts
  Oracle comes with default admin accounts like sys and system that you can leverage. If you installed the full Oracle database alongside sqlplus, you might have set their passwords during setup. If you forgot or didn't set them, use OS authentication to reset:

  1. Switch to the Oracle system user (created during installation):

     su - oracle
     

  2. Log into sqlplus without a password using OS authentication:

     sqlplus / as sysdba
     

  3. Reset the system account password once you're in:

     ALTER USER system IDENTIFIED BY your_new_secure_password;
     

     Now you can log in normally with sqlplus system/your_new_secure_password.

• Verify if you have a local Oracle instance
  Typing just sqlplus defaults to connecting to a local Oracle instance (usually named ORCL). If you only installed the sqlplus client (not the full database), you'll need to connect to a remote Oracle server. Use this format for remote login:

  sqlplus your_username/your_password@//remote_server_ip:port/service_name
  

• Check environment variables
  Make sure your ORACLE_HOME and PATH are set correctly so sqlplus can locate the database instance. Run these commands to verify:

  echo $ORACLE_HOME
  echo $PATH
  

  If they're missing, add these lines to your ~/.bashrc file:

  export ORACLE_HOME=/path/to/your/oracle/install
  export PATH=$ORACLE_HOME/bin:$PATH
  

  Then apply the changes with source ~/.bashrc.

Quick note: If you only installed the sqlplus client (no local database), you must have valid credentials for a remote Oracle server to use sqlplus fully.

内容的提问来源于stack exchange，提问作者Harish Chauhan