September 2004
Intermediate to advanced
710 pages
24h 25m
English
Content preview from SQL in a Nutshell, 2nd 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,
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.
Keywords and Reserved Words
Just as certain symbols have special meaning and functionality within SQL, certain words and phrases have special significance. SQL keywords are words whose meanings are so closely tied to the operation of the RDBMS that they should not be used for any other purpose; generally, they are words used in a SQL statement. (Note that they can be used as an identifier on most platforms, but they shouldn’t be.) For example, the word “SELECT” is a reserved word and should not be used as a table name.
Tip
It is generally a good idea to avoid naming columns or tables after a keyword that occurs in any major platform, because database applications are frequently converted from one platform to another.
Reserved words, on the other hand, do not have special significance now, but they probably will in a future release. To emphasize the fact that keywords should not be used as an identifier, but nevertheless could be, the SQL standard calls them “nonreserved keywords.” Reserved words and keywords are not always words used in SQL statements, but may be words commonly associated with database technology. For example, CASCADE is used to describe data manipulations that allow their action, such as a delete or update, to “flow down,” or cascade, to any subordinant tables. Reserved words and keywords are widely published so that programmers will not use them as identifiers that will, at some later revision, cause a problem.
SQL2003 specifies its own list of reserved words and ...
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.