March 2001
Intermediate to advanced
640 pages
14h 9m
English
book
Sams Teach Yourself Transact-SQL in 21 Days, Second Edition
by Lowell Mauer, David Solomon, Bennett McEwan
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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.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.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.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.
Summary
Congratulations, you have made it to the end of the day. If your head hurts, don't worry, it's temporary. Today, you learned everything you ever wanted to know about subqueries, but didn't know to ask. You saw how to use subqueries that return single results, as well as subqueries that return lists, and subqueries that do the work of inner joins. In addition, you saw how to use subqueries to return aggregate information, which you would then use in a normal query (one that doesn't use a GROUP BY clause).
You also learned how to use both the IN and EXISTS conditions in the WHERE clause to select data when using subqueries. In tomorrow's lesson, you will learn how to manipulate the data that is in the database by using the INSERT, UPDATE, ...
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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.