How to Divide one Column by Another in MySQL or Oracle

Problem

You want to divide one column by another in MySQL or Oracle.

Example

An online store has an orders table with data in the columns order_id, total_order_payment, and item_count.

Let’s say we want to extract the average cost per item for each order, i.e., the total payment for the order divided by the item count.

Solution

A query to do this is:

SELECT
  order_id,
  total_order_payment / item_count AS average_item_cost
FROM orders;

Here’s what you get with this query:

Discussion

To divide a column by another in MySQL and Oracle, use the division operator /. Put the first column or expression before the / operator and the second column or expression after the / operator.

You may use the division operator / to divide by constant values as well. For example, to find out the price with a 50% discount, use this query:

SELECT 
  order_id, 
  total_order_payment / 2 AS payment_after_discount
FROM orders;