If you want to query from two tables with a left outer join, you can use the LEFT OUTER JOIN ... ON clause in the FROM clause. The following query returns output with a left outer join from two tables: departments and employees. The join condition is that the manager ID in the departments table equals to the employee ID in the employees table:

SQL> set NULL 'NULL'

SQL> SELECT d.department_name, e.first_name, e.last_name

2 FROM departments d LEFT OUTER JOIN employees e

3 ON d.manager_id = e.employee_id;

DEPARTMENT_NAME   FIRST_NAME   LAST_NAME

-------------------- -------------------- --------------

Administration  Jennifer   Whalen

Marketing    Michael   Hartstein

Purchasing   Den   Raphaely

Human Resources   Susan   Mavris

Shipping   Adam    Fripp

IT    Alexander  Hunold

......

Treasury   NULL    NULL

Corporate Tax   NULL    NULL

Control And Credit  NULL    NULL

Shareholder Services NULL    NULL

Benefits   NULL    NULL

Manufacturing   NULL    NULL

Construction   NULL    NULL