Oracle-External Connection

Left: Select E. last_name, E. department_id, D. department_name From Employees E Left     Join Administrative ments d On (E. department_id = D. department_id );

Equivalent

Select E. last_name, E. department_id, D. department_name From Employees E, departments d Where E. department_id = D. department_id ( + ); Right: Select E. last_name, E. department_id, D. department_name From Employees E Right   Join Administrative ments d On (E. department_id = D. department_id );

Equivalent

Select E. last_name, E. department_id, D. department_name From Employees E, departments d Where E. department_id ( + ) = D. department_id; All external connections: Select E. last_name, E. department_id, D. department_name From Employees E Full     Join Administrative ments d On (E. department_id = D. department_id ); Equivalent select E. last_name, E. department_id, D. department_name from employees e, ments d where E. department_id ( + ) = D. department_id (+);