SQL Fundamentals · Aggregation & Grouping · Lesson 15 of 17
Aggregate Functions
Concept
Aggregate Functions
COUNT, SUM, AVG, MIN, and MAX compute a single summary value across many rows.
By the end of this lesson
- Explain the core idea behind Aggregate Functions.
- Predict output before running a change.
- Test one realistic and one unusual input.
- Use the result to make the next decision.
How to study this page
- 1. Read one concept.
- 2. Change the example.
- 3. Run, compare, and explain.
- 4. Complete the challenge below.
Self-check before continuing
Without looking at the example, describe what changes when you modify one input in Aggregate Functions. Then reopen the editor and prove your explanation with a small test.
You are ready to continue when you can predict, test, and explain the result.
Your turn
Write a query that returns the oldest age in the students table using MAX.
Need a nudge?
Ask about this lesson or your next move. The guide explains the path without taking the work away from you.
Ready for the next lesson?
Mark this lesson complete when you have finished the exercise.
Loading editor…
Console