A: PHP is a great language for web programming and it would serve you well to learn it.  My first suggestion for learning PHP is to sit down with a good php book. Your best bet is to go to Amazon.com and search for PHP introductory books or books for PHP beginners, and based on the reviews their and the publishers you like, get a book.  For example, I’ve always liked Wrox books.  As much as people don’t like sitting down with a book, I think it’s important to really sit down and learn the fundamentals first.

For more specific php help, your best bet (once you’ve tried to work it out on your own, of course) is to go to one of many php forums.  I’ve always found the forums at DevShed.com to be very helpful. If you do a search of their php forums you will likely find an answer.  Another good bet is to do a Google search for your specific problem or error.

Just remember, PHP is a very popular language, and while it can get frustrating at times like any other programming language, rest assured that you are probably not the only person to run into your specific problem — and an answer is out there!

The following method is a simple solution to store all of your queries in one file and access them as needed. Please note that I am not advocating this as a “best practice” as there are many great articles on how to truly separate your presentation layer and your data layer, but this works.

I always have a database.php file that stores the connection data and has the related connection functions. So to continue with this “separation” concept, create a queries.php file.

To this file I simply add a variable that stores the specific query. So for example, I would add the following variables:

$getAuthors = "SELECT * FROM authors";
$getBooks = "SELECT * FROM book";

and so on with your queries.

Turning to the page that displays the results — the one that actually uses the query — (lets call it authors.php), I have the include statement:

include "queries.php";

and of course the code to access my database:

link_id = db_connect();
[here you can use whatever particular code you personally use to connect to a mysql database]

Then I simply populate the $sql variable (where I previously would have stored the actual code of the query), with the following:

$sql = $getAuthors;

To show you where it goes, I’m using the code: $result=mysql_query($sql) or DIE(mysql_error());

Again, the specifics don’t really matter other than that instead of hard-coding the sql query text for the $sql variable, you are simply referencing a variable in another file.

Now if you decide to update, change or modify the query, you can do it in one place — in the queries.php file.

So while this may not be the best method of handling this situation, it does work, and it does save time.

I wanted to make sure that 1) there was only one character in the querystring, and 2) that the character was a letter — uppercase or lowercase.

Here’s the regular expression pattern  I used:

$pattern = '/^[A-Za-z]{1}$/';

I used the following function to test the pattern, where $variable is the queryString that is passed from the calling page.  The “good” and “not good” output text are for diagnostic use and of course, will be removed later on.

function letterCheck($variable) {
$pattern = '/^[A-Za-z]{1}$/';
if (preg_match($pattern, $variable)) {
echo "RegExp is good";
return 1;
}

else {
echo "RegExp is not good. " . $variable . " does not match the criteria. ";
return 0;
}
}

That’s it.