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468. AVG with JOIN

Learn how AVG calculates averages across related records using JOIN.

📘 Lesson 468 of 728 ⏱ 11 min 🎯 Intermediate

AVG calculates the arithmetic average of numeric values and can be used with JOIN to analyze related records.

Average order value, average salary, average transaction amount, and average rating are common business metrics.

Calculate the average order value for each customer.

SQL 
SELECT
    c.CustomerName,
    AVG(o.OrderAmount) AS AverageOrderValue
FROM Customers c
LEFT JOIN Orders o
    ON c.CustomerID = o.CustomerID
GROUP BY c.CustomerName;

AVG with JOIN is useful in customer analysis, financial analysis, sales reporting, and performance measurement.

  • AVG calculates the arithmetic mean.
  • NULL values are ignored.
  • JOIN connects the values to related entities.
  • GROUP BY calculates separate averages.
  • Average calculations should consider the correct population.
Can AVG be used with JOIN?

Yes. AVG can calculate averages across numeric values from related joined records.

Does AVG include NULL values?

No. AVG ignores NULL values when calculating the average.

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