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
Content preview from Sams Teach Yourself Transact-SQL in 21 Days, Second Edition
Become 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,
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.
Q&A
| Q1: | Can I use more than one subquery in a single statement? |
| A1: | Yes. In fact, you can use as many subqueries as you like, just as long as you do not exceed the nesting level limit of 32. |
| Q2: | Can I mix subqueries and joins in the same query? |
| A2: | Why not? Some programmers find that doing this helps them understand how the server is actually creating their result set. |
| Q3: | What happens if the subquery I am using returns a null, or if it returns no rows at all? |
| A3: | If a subquery returns a NULL, the outer query will simply compare the specified column to a NULL value. This won't cause an error, but it might not be what you wanted. If the subquery returns no rows (empty set), again, there would be no error, but you would not get any rows back from the ... |
Become 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,
and much more.
Read now
Unlock full access
More than 5,000 organizations count on O’Reilly
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.