October 2002
Beginner
864 pages
18h 41m
English
Content preview from Sams Teach Yourself SQL in 21 Days, Fourth EditionBecome an O’Reilly member and get unlimited access to this title plus top books and audiobooks from O’Reilly and nearly 200 top publishers, thousands of courses curated by job role, 150+ live events each month,
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Managing Constraints
How do you manage constraints in a database? First, you must understand the relationship between tables in your database. What are the dependencies? What columns depend on other columns? Can a column contain a NULL value, or must it contain data? Is there a list of allowed values for each column? How are the tables accessed by an application?
You should spend a lot of time upfront in the design phase of your database to ensure that you have a good, sound structure. Once you have created your database, you must understand how the tables are related and know what constraints there are in the database. If you do not know what all of the constraints are in your database (and you probably won't if your database is very big), you ...
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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.