الاخوة الاعزاء: شرح الInline Views

[omar-alreyati]

الاخوة الاعزاء : ارجو منكم شرح الInline Views، وما هي الفائدة من استخدامها، مع بعض الأمثلة لو سمحتم.



وشكراً

[Osama Soliman]

Inline Views

•An inline view is a subquery with an alias (or correlation name) that you can use within a SQL statement.

•An inline view is created by placing a subquery in the FROM clause and giving that subquery an alias.

•An inline view is not a schema object.

•The subquery defines a data source that can be referenced in the main query

SELECT  a.last_name, a.salary, a.department_id, b. maxsal
FROM  employees a, 
(SELECT  department_id, max(salary) maxsal
FROM  employees
GROUP BY department_id) b
WHERE   a.department_id = b.department_id
AND    a.salary < b.maxsal;