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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Joining Multiple Tables in a Single SELECT Statement
Like Dorothy in The Wizard of OZ (who had the power to return home all along), you have had the power to join tables since Day 2, “Introducing the Query,” when you learned about SELECT and FROM. Unlike Dorothy, you don't have to click your heels together three times to perform a join. The two following subsections cover some fundamental material with which you need to begin in order to understand join operations. First, we show you the simplest form of the join, and then how to select a common key between tables through which to perform the join operation. We will use the following two tables, named, cleverly enough, TABLE1 and TABLE2.
Note
The queries in today's examples were produced using ...
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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.