Understanding Database Views

What is the primary benefit of using views in a database?

• They reduce the need for database backups.

• They allow for more complex queries.

• They make it easier to search and manage data.

• They increase the size of the database.

How can sensitive data be protected when creating a view?

• By renaming the sensitive columns.

• By creating a backup of the table.

• By excluding sensitive columns from the view.

• By encrypting the entire table.

What SQL command is used to combine results from two SELECT queries?

• JOIN

• MERGE

• INTERSECT

• UNION

How can you ensure unique IDs when combining data from two tables?

• By prefixing IDs with a unique letter.

• By using a random number generator.

• By using the same ID for all entries.

• By deleting duplicate IDs.

What is the purpose of a CROSS JOIN in SQL?

• To filter rows based on a condition.

• To combine rows from two tables without a condition.

• To update rows in a table.

• To delete rows from a table.

What function can replace null values with a default value in SQL?

• COALESCE

• NVL

• NULLIF

• ISNULL

What is the result of a CROSS JOIN between two tables?

• A filtered set of rows based on a condition.

• A set of rows with only matching entries.

• A Cartesian product of the two tables.

• A set of rows with no duplicates.

What is the main advantage of using the COALESCE function in a view?

• It replaces null values with a specified value.

• It allows for the use of multiple tables.

• It increases the speed of queries.

• It encrypts sensitive data.

What is a key benefit of using views for database security?

• They restrict access to specific data.

• They automatically encrypt all data.

• They provide access to all data in the database.

• They allow users to modify the database structure.

Why might a database designer choose to use a view instead of querying multiple tables directly?

• To allow users to modify the database schema.

• To reduce the number of tables in the database.

• To simplify data retrieval for users.

• To increase the complexity of queries.