Example Querying a System View

This section includes an example querying a system view.

• Querying a System View

Querying a System View

You can query a system view using procedures.

This example queries the USER_SOURCE system view to examine the source code of procedure query_emp from the example in Using IN and OUT Parameters. You must create that procedure before completing this example.

Command> SELECT SUBSTR (text, 1, LENGTH(text)-1)
         FROM user_source
         WHERE name = 'QUERY_EMP' AND type = 'PROCEDURE';

This produces the following output:

< PROCEDURE query_emp >
< (p_id IN employees.employee_id%TYPE, >
<  p_name OUT employees.last_name%TYPE, >
<  p_salary OUT employees.salary%TYPE) IS >
< BEGIN >
< SELECT last_name, salary INTO p_name, p_salary >
< FROM employees >
< WHERE employee_id = p_id; >
< END query_emp; >
9 rows found.

Note:

As with other USER_* system views, all users have SELECT privilege for the USER_SOURCE system view.