I was reading through SQL in easy steps, 3rd Edition and made it to page 152 where it covered Sub-query calculated fields. It’s a fancy way of saying a SELECT statement within a SELECT statement, but isn’t that hard to grasp if you’re familiar with how variable interpolation works with Bash or similar shells.
My problem was understanding how even though a column wasn’t listed as one to be returned by SELECT it was seemingly returned as a byproduct of an ORDER BY statement. I couldn’t find this mentioned in any of the MySQL documentation or another MySQL book I have so I was getting pretty frustrated. I fired my MySQL this morning and opened up subquery-calc.sql and had a good laugh: The mental block I was having was due to an error in the book’s code that wasn’t present in the SQL file.
I fired off an errata report in the hopes that it will be correct in future printings so others won’t be as confused as I was.
The author’s page for this book is now offline. Please see this post for more details, including where you can still obtain the library sources and other updated content for the book.
I picked up this book and the follow-up You Can Program in C++: A Programmer’s Introduction book several years ago while flailing about in an attempt to learn C++. The short version of why I didn’t succeed was that I didn’t have the required patience to take things slow and fully understand each new idea before moving on.
Well, I’m forcing myself to have the required patience this time around (started most recent attempt Sept 2011), and I’ve made good progress going through Ivor Horton’s Beginning Visual C++ 2008.
Now that I’ve made it through the first eight chapters, I’m seriously considering taking a break and going back to You Can Do It! A Beginner’s Introduction to Computer Programming. There are several reasons for this, and I’m thinking the biggest one is that both of these books by Francis Glassborow are sub-400 pages, while Ivor Horton’s Beginning Visual C++ 2008 is 1392 pages. To be fair, those pages are not only dedicated to Standard C++, but code specific to Microsoft Visual C++ and C++/CLI. Still, with only 543 of 1392 pages down, I’m thinking I need the emotional pick-me-up from completing a smaller book. Then I can return to that one.
All of that said, I’ve just started looking at the errata, the contents of the CD that came with the book and the latest updates to the CD contents and source code.
I had no idea how spoiled I had become from always heading to the website to grab the very latest and authoritative version of software/code. A few things I’ve figured out:
- The CD contents are superseded by the contents available on the CD Substitute page.
- The fgwlib library sources from the Resources page supersede the sources available from tutorial.exe on the CD Substitute page. Oddly enough, some of the comment misspellings that were fixed in the CD Substitute page are back in the latest fgw library sources, so it’s likely the author wasn’t using version control.
- The Quincy download link on that page is no longer working.
- There is a newer version of the IDE used by the book, Quincy, available here.
The fgwlib library sources available from the Resources page supersede all other library sources.
Now that I’ve figured that out, I’m off to build the library to work with the latest MinGW install.