Answers to Chapter 9

  1. "Which of the following data types are incorrect" The answers are "b" and "d": VARCHAR fields can only hold 255 characters, and LONGINT doesn't exist in MySQL, you should use BIGINT.

  2. "Suggest the ideal data type for the following fields". For "First name" you should have answered with a VARCHAR of sorts, for "Age" a small INT field, for "Height" another small INT field (and convert things like feet and inches into plain old inches), and for "Life story" I think TEXT should suffice.

  3. "When are LOW_PRIORITY-marked writes executed" The answer is "c": when no more reads remain.

  4. "Temporary tables are automatically deleted when your scripts ends: true or false" True.

  5. "Which of the following statements are true about indexes" The correct answer is "e".

  6. "You can emulate subselects using multiple individual queries: true or false" True, but hard work!

  7. "Unbuffered queries allow you to start reading in the result of a query before the query has been finished: true or false" True, but don't try to count the number of rows until the query has finished executing.

  8. "What is SQLite's key advantage over MySQL and other DBMSs" It doesn't use a client/server architecture, so is easier to install and distribute.

  9. "Using PEAR::DB is usually as fast if not faster than standard database calls: true or false" False: PEAR::DB is pretty slow, actually.


Want to learn PHP 7?

Hacking with PHP has been fully updated for PHP 7, and is now available as a downloadable PDF. Get over 1200 pages of hands-on PHP learning today!

If this was helpful, please take a moment to tell others about Hacking with PHP by tweeting about it!

Next chapter: Answers to Chapter 10 >>

Previous chapter: Answers to Chapter 8

Jump to:


Home: Table of Contents

Copyright ©2015 Paul Hudson. Follow me: @twostraws.