-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 On 05/04/2010 07:30 PM, Doug wrote: > Sure, if the book is just a copy-paste of the website, > that's not too helpful. But hopefully things are stated differently, or > examples are given which can be valuable.
I picked some random spots to check: "GROUP BY" - several paragraphs in the book and 3 sentences in the SQLite doc. I think they could both do with a lot of improvement especially in showing how it differs from "ORDER BY", using and not using aggregate functions etc. In both cases there is no way I could read the description and then explain what it actually did given some examples unless I knew SQL already. Date/Time - A "chapter" in both and both are pretty good, but with a little more content and warnings in the book, but for example the book omits to mention how Vista will screw up timezone calculations. It also advises on the textual representation being less efficient but doesn't give useful advice on how much. For example if it takes 5% longer to sort a million dates stored in text vs number then that may be acceptable but if it is 500 times as much then not. FTS3 - The book is virtually useless despite having a page or two. You'd still have to look online to work out how it actually works, how to add data, query formats, stemming etc. Virtual tables - The online doc gives better information on the distinction between xCreate and xConnect. The book pretty much avoids any detail on xBestIndex. This is by far the most complex method and very hard to understand and get right until you have worked with it a few times. SQLITE_DEFAULT_FILE_FORMAT - Book names the SQLite version that introduced the new format (3.3.0) and adds a caveat about SQL parsing on open. A little more useful than web site but then the web site does have a more detailed page about backwards compatibility and for example mentions which versions can't cope with a database where ALTER TABLE ADD COLUMN has been used. ALTER TABLE - both have a page of doc with the web site mentioning the version issue and the book not. The wording is a little different between them in some places but neither is clearer. Neither gives an actual example. abs() - One page in the book and one paragraph on the web site. The web site is better as it explains what happens if you pass in a string that cannot be converted to a number as well as Abs(-MAXINT64) glob() - Tersely described on both, both referring to the GLOB SQL keyword. Of course you can click in the web site but not a book. Book is better for GLOB keyword actually mentioning what the match syntax is, but excludes any examples. Neither mentioned anything about the international issues (eg does [a-z] also include é? max() - Book separates scalar vs aggregate into separate pages, neglects to mention the collation functionality that is described on the web site. pragma index_info - Two sentences, one diagram, no example in the book and one sentence gibberish on the web site. Neither the book nor the site go into usable detail about Unicode, locales, internationalization, localization, the right way to deal with it in SQLite etc. So on the whole the reference stuff in book doesn't really add anything over the web and can be wrong or misleading. It could be better by giving examples. It could show what happens when irregular or out of bounds values are supplied. It could give performance considerations. And if it was removed the book would be a lot shorter. (Presumably computer books are bought on thickness no matter how much of that repeats what you can see in your browser.) Although I may seem negative, this is a constant glass half full thing that really annoys me. Sure it is a lot of effort to author a book to the point that it is somewhat equivalent to the web site, but so many times things stop there. To me it is only what happens beyond that that makes a book valuable and I'm hoping that will happen with this one. Roger -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.10 (GNU/Linux) Comment: Using GnuPG with Mozilla - http://enigmail.mozdev.org/ iEYEARECAAYFAkvjQvIACgkQmOOfHg372QQP5wCePiqnhJS/XFKTEyoJBrKiqqPb P34AoI5OTGlLZe/Dmp9yniNVxJ8GKCyy =MvMI -----END PGP SIGNATURE----- _______________________________________________ sqlite-users mailing list [email protected] http://sqlite.org:8080/cgi-bin/mailman/listinfo/sqlite-users
