Techlens Global Database Engineer Interview Questions and Answers

Aggregate functions in SQL are used to perform calculations on a set of values and return a single value.

• Aggregate functions include SUM, AVG, COUNT, MIN, and MAX.

• They are often used with the GROUP BY clause to group the results based on certain criteria.

• Examples: SELECT SUM(sales) FROM orders; SELECT AVG(age) FROM employees GROUP BY department;

• Aggregate functions ignore NULL values unless specified.