Display Data from Multiple Table
Cartesian -Products:
Without any joining condition return the value. Is called a cartesian product.
Example:
Select employees. employees_id, employees. last_name , employees.department_id,departments.department_id,departments.location_id from employees. department;
Equi_Joins:
One table to another table equally joins is called Equi_Joins.
Example:
Select employees. employees_id, employees. last_name , employees.department_id,departments.department_id,departments.location_id from employees. Department where employees.department_id = department.department_id;
Non Equi_Joins:
Too many tables join.
Example:
Select employees. employees_id, employees. last_name , employees.department_id,departments.department_id,departments.location_id from employees. Department
where employees.department_id
Between department.department_id and department.location_id;
Outer_Joins:
When we find with the null value.
Example:
Select employees. employees_id, employees. last_name , employees.department_id,departments.department_id,departments.location_id from employees. Department
where employees.department_id (+)= department.department_id;
Self_Join:
When Join same table that is called self_join .
Example:
Select worker.last_name || ‘work as’ || manager.last_name from employees worker , employees manager where worker.manager_id =manager.employee_id;
Oracle SQL Joins
