CONNECTING TO THE HR SCHEMA

In this section, you connect to Oracle Database by using the SQL*Plus utility, and you unlock the HR schema.


Open a terminal window and execute the oraenv command to set the environment variables.
. oraenv




Execute the following statement to connect to the database as a system administrator:
sqlplus sys/<password> as sysdba;




By default, the HR schema is locked. Execute the following statement to unlock the HR schema.
ALTER USER hr IDENTIFIED BY hr ACCOUNT UNLOCK;



Execute the following command to connect to the HR schema:
CONNECT hr/hr;




The DESCRIBE command provides a description of a specified table or view. The description for tables and views contains the following information:


• Column names
• Whether null values are allowed (NULL or NOT NULL) for each column
• Data type of columns, such as DATE, NUMBER, VARCHAR2 
• Precision of columns, such as VARCHAR2(50)

Syntax: DESC[RIBE] <table>
Execute the following command to view the description of the EMPLOYEES table:
DESCRIBE EMPLOYEES;