TAILIEUCHUNG - SQL PROGRAMMING STYLE- P38

SQL PROGRAMMING STYLE- P38:Im mot trying to teach you to program in SQL in this book. You might want to read that again. If that is what you wanted, there are better books. This ought to be the second book you buy, not the first. I assume that you already write SQL at some level and want to get better at it. If you want to learn SQL programming tricks, get a copy of my other book, SQL for Smarties (3rd edition, 2005). | 32 CHAPTER 2 FONTS PUNCTUATION AND SPACING 3. Put a new line or at least a space after a semicolon to separate statements. 4. Put a space between words even when you could crowd them together. Exceptions If SQL does not work the same way as English then you have to follow the SQL syntax rules. Many of the code-formatting habits people have go back to habits they were taught by programmers who grew up with punchcard data processing. Because we have video terminals and text editors today a lot of habits no longer have any basis. The practice of putting a comma in front of a single variable on a single line goes back to punchcards. It was often difficult for programmers to get to a keypunch machine to create their decks of cards. In this format you could pull or insert a card to change your code. There is no excuse for this practice since we now have video terminals. English and European languages are read left to right and then top to bottom. This scanning pattern is so deeply learned that we arrange schematics comic books maps and other graphics the same way. To see how much changing that order can throw you off try to read a Japanese or Chinese comic book. The panels are in right-to-left order and the Chinese word balloons are read top to bottom. This is why typographers have a rule that you do not set long words V E R T T I C A L L Y. Did you spot the misspelling About one-third of readers do not. Likewise it is difficult to locate duplicates and errors in those long oid Proprietary Reserved Words if a Standard Keyword Is Available in Your SQL Product 33 vertical lists of names. SQL formatting can use vertical alignment to advantage in other places but in things that should be chunked together. Use Full Reserved Words Rational SQL allows you to skip some reserved words and to abbreviate others. Try to use the full forms to document the program. This is a good thing in COBOL and it works in SQL as well. For example an alias can be written with or without an AS

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