Keertana Finserv SQL Developer Interview Questions and Answers

Functions in SQL are reusable code blocks that perform a specific task.

• Functions can be user-defined or built-in

• They can return a single value or a table of values

• Examples include SUM(), AVG(), and GETDATE()

DCL stands for Data Control Language, used to control access to data stored in a database.

• DCL commands include GRANT, REVOKE, and DENY.

• GRANT is used to give specific privileges to a user or role.

• REVOKE is used to take back privileges that were granted.

• DENY is used to explicitly deny access to a resource.

A subquery is a query nested within another query to retrieve data based on the results of the outer query.

• Subqueries can be used in SELECT, INSERT, UPDATE, and DELETE statements.

• Subqueries can be correlated or non-correlated.

• Example: SELECT * FROM table1 WHERE column1 = (SELECT column2 FROM table2 WHERE condition);