I have a set of sales transaction data containing more than 1 item purchased. Every item sold has a category. I would like figure out which categories are most commonly ordered together.
The data is more or less like this:
Transaction ID|Item ID | Sales Quantity|Item Category 1 Apple 1 Fruit 1 Banana 1 Fruit 1 Carrot 2 Vegetable 2 Carrot 1 Vegetable 2 Ice Cream 2 Dessert 3 Squash 2 Vegetable 3 Chocolate 2 Dessert 4 Apple 1 Fruit 4 Carrot 1 Vegetable 4 Doughnut 1 Dessert
Just eyeballing above you can see that there are a high amount of vegetable-dessert pairings on the same transaction. But now imagine that we have 250,000+ transactions in the data set and dozens of categories. I'm looking to discover cross category sales only. Not interested in Apples and Bananas (Fruit-Fruit) pairs.
I think I can teach myself how to code the analysis, but I'm just not sure what this is called or what to Google. Any thoughts?