Solution to Oracle user connection failure

The failure of Oracle user connection makes us a headache. The following describes how to solve the failure of Oracle user connection and hopes to help you learn about Oracle user connection.

After installing oracle11g, I want to enable the built-in SQL plus for learning, and then follow the prompts to use the Sys user to connect to the database. If I lose the SQL Plus, an error is prompted several times:
Error: the account is locked

This may be due to the following reasons.

1. Failed to log on multiple times (the password may be incorrect );

2. the user is manually locked by the Administrator;

3. the user password expires, the password is not modified on time, and so on.

It seems that Scott cannot log on, and I try to log on with the user "system". I remember that I was prompted to enter the password when installing Oracle 11g, then I lost one by myself. As a result, I tried the connection with my original password. It can be seen that in Oracle 11g system, the user's password is not the default, but set by yourself during installation.

After logging in with system, run the following command:
SQL> alter user Scott account unlock;
The user has changed.

This completes the unlock operation. Next, you can set a new password for Scott.
Modify Scott's logon password:
SQL> alter user Scott identified by tiger;
The user has changed.

Now you can log on with Scott and tiger!
SQL> conn Scott/Tiger
Connected.