Which SQL command should a database administrator use to create a view named 'RecentOrders' for orders placed within the last 30 days?

• A. CREATE TABLE RecentOrders AS SELECT ...
• B. CREATE VIEW RecentOrders AS SELECT ...
• C. CREATE INDEX RecentOrders AS SELECT ...
• D. ALTER VIEW RecentOrders AS SELECT ...

Answer: (B)

The correct approach to create a view named 'RecentOrders' that encapsulates orders placed within the last 30 days is to use the command designed specifically for this purpose, which is the command to create a view.

Creating a view in SQL allows for the storage of a query that can be treated like a table. This is particularly useful for simplifying complex queries, encapsulating business logic, or presenting data in a specific way without altering the original tables. The syntax "CREATE VIEW RecentOrders AS SELECT ..." directly indicates that you are defining a new view called 'RecentOrders' based on a selection of data from one or more underlying tables.

This command allows database administrators to tailor the data by defining what constitutes the 'RecentOrders' view, potentially including filtering conditions like those for the last 30 days.

In contrast, the other options do not serve the intended purpose:

• Creating a table is not suitable here because you want a virtual representation (the view) of the current data, not a new table with its own storage.

• An index is used to improve the speed of data retrieval and does not encapsulate a query, making it irrelevant for the task of creating a view.

• Altering a view is meant for modifying an existing