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RDBMS FUNDAMENTALS - End-user's View of a Database
Views : Views are relations that are derived from one or more source tables. Views have the following features:
Views let you restrict the access to data so that end-users see data relevant to them.
Views do not physically exist in the database and only their definition is stored by an RDBMS.
An RDBMS accesses the source tables for data to be retrieved from a view.
Any changes that users make to views do not reflect in the source tables if the view has been created using a Join condition.
Views created WITH CHECK OPTION allows for an added measure of security in a view. For example, the user will not be able to insert or update a row that could not be selected by the view-with check option prevents this from happening.
CREATE VIEW : A view can be created using the CREATE VIEW command.
Syntax : CREATE VIEW view-name (column-names) AS query.
Retrieving Data from a View : Once you create a view, you can retrieve data from it using the SELECT command, just as you do for a table.
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