October 2015
Beginner
206 pages
4h 4m
English
Content preview from MariaDb Essentials
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Foreign keys
As you know, relationships exist between the tables in a relational database. This means that the rows in a table are usually associated to the rows in another table or multiple tables.
Creating relationships between tables
Let's see an example. Suppose that our online store sells several types of products. We don't want to display them all together, because it would be confusing for most users. Instead, we need to separate our products by category.
So, first we will create a table for the product categories. We need to store the category name, a description, and of course an id that will be the primary key:
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O’Reilly covers everything we've got, with content to help us build a world-class technology community, upgrade the capabilities and competencies of our teams, and improve overall team performance as well as their engagement.Julian F.
I wanted to learn C and C++, but it didn't click for me until I picked up an O'Reilly book. When I went on the O’Reilly platform, I was astonished to find all the books there, plus live events and sandboxes so you could play around with the technology.Addison B.
I’ve been on the O’Reilly platform for more than eight years. I use a couple of learning platforms, but I'm on O'Reilly more than anybody else. When you're there, you start learning. I'm never disappointed.Amir M.
I'm always learning. So when I got on to O'Reilly, I was like a kid in a candy store. There are playlists. There are answers. There's on-demand training. It's worth its weight in gold, in terms of what it allows me to do.