Mathematical Operators

Part of the Fundamentals section of Coddy's SQL journey — lesson 23 of 72.

In SQL, you can perform calculations directly with column values in your queries. This is useful when you need to compute new values based on existing data. For example:

Operator	Operation
+	Addition
-	Subtraction
	Multiplication
/	Division

SELECT price + 10 as increased_price,
       price - 10 as reduced_price,
       price  10 as multiple_price,
       price / 2 as half_price
FROM products;

Important note about division: When dividing integers in SQL, the result depends on the data types involved:

Integer ÷ Integer = Integer (truncated): 7 / 2 = 3 (not 3.5)

Integer ÷ Float = Float: 7 / 2.0 = 3.5

Float ÷ Integer = Float: 7.0 / 2 = 3.5

To get decimal results when dividing integers, make sure at least one operand is a float (use values like 2.0 instead of 2).

Challenge

Easy

Available tables and columns:
products: id, price, quantity

Create two calculated columns:

First column named high_mix_op:
- Take the price column
- Multiply it by 2
- Subtract 20 from the result
Second column named low_mix:
- Take the quantity column
- Divide it by 1.5
- Add 5 to the result

Cheat sheet

SQL supports arithmetic operations directly with column values using these operators:

Operator	Operation
+	Addition
-	Subtraction
*	Multiplication
/	Division

You can perform calculations and assign aliases to the results:

SELECT price + 10 as increased_price,
       price - 10 as reduced_price,
       price * 10 as multiple_price,
       price / 2 as half_price
FROM products;

Try it yourself

Test yourself

This lesson includes a short quiz. Start the lesson to answer it and track your progress.

Mathematical Operators

Cheat sheet

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