Lesson 19: Finding the average of numerical values using the AVG function.
What is the Average?
In maths when we talk about the Average, we actually mean the Mean. The easiest way to think of doing it manually is to add up all of the numbers in the set and then divide the total by however many numbers you had in the list.
So if we had a set of numbers like this: 1 2 3 4 5 6 7
Our sum total would be: 1+2+3+4+5+6+7 = 28
The number of numbers in our set is 7.
So the Average (or Mean) is 28 / 7 = 4.
I didn't ask for a maths lesson. How about in SQL?
If we want to find out what the AVERAGE (or MEAN) value within a specified column is, we use the AVG function,
e.g.
SELECT AVG(PlayerWage) FROM Players;Which would give us the average player's wage from within our "Players" data table.
Quiz Time.
The Question.
We can see by looking at the data table that the cost of making an Avengers movie went up quite dramatically over time.The price of success.
How much did an average Avengers movie cost to make though?
The Data.
The Editor.
Show Answer
The Answer.
Correct SQL:
SELECT AVG(budget) FROM movies;