TweetFollow Us on Twitter

PHP And MySQL, Together At Last

Volume Number: 21 (2005)
Issue Number: 6
Column Tag: Programming

Getting Started

PHP And MySQL, Together At Last

by Dave Mark

Interwoven in my last six columns or so were columns that showed you how to install and test PHP and MySQL. The PHP and MySQL columns all dealt with PHP and MySQL in isolation. The PHP code did not access a MySQL database, and the MySQL database access was all done via the Terminal and not via a PHP encrusted web page. In this month's column, we'll verify that both are installed and available, then see if we can't make them play nicely together. Let's start by verifying our install.

Checking Your PHP Install

If you are new to PHP, make your way over to http://www.php.net and browse through their documentation. If you've installed even a reasonably recent version of Mac OS X on your machine, you should have PHP installed. One solid clue that you do have PHP installed can be obtained by typing this command in Terminal:

$ ls /usr/local/

If the result of this command includes the text "php5", chances are, you're all set. If it doesn't, visit Mark Liyanage's wonderful PHP site:

http://www.entropy.ch/software/macosx/php/

Mark has put together an excellent PHP resource for Mac OS X and he does a nice job keeping it up to date. Though, at this writing, the site still lists Mac OS X 10.3 as the most recently supported, I had no trouble using his install package on my Tiger machine. Obviously, you'll want to backup your machine first, just in case something does go wrong.

Hopefully, you do have PHP installed on your machine already. Regardless of how you got there, once you've got PHP 5 installed, here's a simple test to make sure you're all good.

Launch your favorite text editor, be sure it is set to save as plain-text, create a new file, then enter this text:

<?php
phpinfo()
?>

Save the file as test.php and place it in the Sites subfolder of your home folder (inside ~/Sites/, aka, /Users/xxxx/Sites/).

To test your new PHP file, launch Safari and type:

http://127.0.0.1/~davemark/test.php

Obviously, you'll replace "davemark" with your own user name. Safari will ask your Apache server to pass the referenced file on to the PHP pre-processor. If all is kosher, a giant table will appear in a Safari window. The beginning of my giant table is shown in Figure 1.


Figure 1. The PHP info table.

Note that my computer is running PHP version 5.0.4. You'll definitely want to check on http://php.net to see if there's a later version available.

Checking Your MySQL Install

If you are new to MySQL, check out http://www.mysql.com. In the March, 2005 Getting Started column, I went through the process of hunting down the proper package for your version of Mac OS X, installing MySQL, starting and shutting down the MySQL server, and setting up the accounts and passwords.

Then, in the April Getting Started, we used the MySQL monitor application, running in Terminal, to build a database and, within that, a table. We added to and deleted rows from the table, and ran some queries to report on the table data. Obviously, I don't want to repeat all that here, but I thought it would be worth repeating a few of the basics, just to make sure we were on the same page.

Start by making sure you have an alias set up for mysql. In Terminal, type this command:

alias

This will list your aliases. Hopefully, one of your aliases will be:

alias mysql='/usr/local/mysql/bin/mysql'

If not, edit the file .profile in your home directory and add this line to the end of it:

alias mysql='/usr/local/mysql/bin/mysql'

Now quit and re-launch Terminal, which will re-execute the commands in .profile. Now, when you type the alias command, your alias should appear. This lets us type mysql to launch the MySQL monitor.

Launch the monitor by typing:

mysql -u root -p

As a reminder, you are launching the monitor with a user of root. You'll be prompted for a password. Type in the password you created when you created your account. Remember, this root is not the same root as your Mac root account. If you are having trouble logging in as root, go back to your setup instructions or to the March Getting Started.

Here's what my monitor looks like:

Welcome to the MySQL monitor.  Commands end with ; or \g.
Your MySQL connection id is 1 to server version: 4.1.12-standard

Type 'help;' or '\h' for help. Type '\c' to clear the buffer.

mysql>

If mysql does not launch your MySQL monitor, either your alias is not set correctly (in which case, go check to see if you've got a file called mysql in the directory /usr/local/mysql/bin/) or you did not install MySQL correctly. If MySQL was not installed correctly, get hold of the March MacTech and follow the installation process, or make your way through the MySQL installation instructions on http://mysql.com.

Assuming your monitor comes up as mine did, type this command:

show databases;

Don't foget the ending semicolon. Here's my result:

mysql> show databases;
+----------+
| Database |
+----------+
| test     |
+----------+
1 row in set (0.18 sec)

mysql>

If you've played with MySQL, you may find yourself with a different set of databases. Not a problem. As long as the command works, you're fine, no matter the result.

Driving MySQL From Within PHP

In April's column, we used the MySQL monitor to create a database, add rows, delete rows, and update values in a table. In the remainder of this month's column, we're going to do the same sorts of things, but do them from within PHP, instead of from the monitor.

Before we get into our PHP example, let's use the monitor to set up a database and table, then populate the table. This approach is pretty typical: Set up the database and table using the monitor, then query/populate the table from your PHP/web interface.

In the monitor, type this command:

mysql> create database products;
Query OK, 1 row affected (0.06 sec)

Next, check to make sure the database got created:

mysql> show databases;
+----------+
| Database |
+----------+
| mysql    |
| products |
| test     |
+----------+
3 rows in set (0.00 sec)

Yup, there it is. Now, let's set products as our database and then create a new table:

mysql> use products;
Database changed
mysql> show tables;
Empty set (0.00 sec)

No tables exist yet. Let's create one:

mysql> create table cables(
   -> name varchar(60),
   -> lengthInCm int(2),
   -> cableType ENUM( 'firewire', 'usb' ),
   -> cableID int(10) auto_increment primary key );
Query OK, 0 rows affected (0.15 sec)

Imagine a database set up for an e-commerce web site, designed to store info on all the site's products. The site sells firewire and usb cables of various lengths. The cables table will store info on the various cables sold by the site. Obviously, this is a very simple example. If this were a real database, we'd want to create multiple tables and have them reference each other. For example, we'd probably create a manufacturer table and have a field in the cables table refer to an entry in that table. This table is not very complicated and would not be terrifically useful in the real world, but it will serve to demonstrate the connection between PHP and MySQL. Read on...

Now let's populate the table:

mysql> insert into cables values ('Varco DX100', 100, 'firewire', 0);
Query OK, 1 row affected (0.13 sec)

Note that we embedded the manufacturer's name in the cable name field. Ick. As I mentioned, this should be a reference to a separate, manufacturer table. For now, this'll do.

Notice that we created an enumerated field. The cableType field can only take on one of two values, either 'firewire' or 'usb'.

We used a value of 0 for the cableID. This asks MySQL to create an index for this entry automatically.

Let's retrieve what we just put in:

mysql> select * from cables;
+------------- +------------+----------- + ------- +
| name         | lengthInCm | cableType  | cableID |
+------------- +------------+----------- + ------- +
| Varco DX100  | 100        | firewire   | 1       |
+------------- +------------+----------- + ------- +
1 row in set (0.04 sec)
Let's add a few more:
mysql> insert into cables values ('Genenco VT100', 100, 'firewire', 0);
Query OK, 1 row affected (0.38 sec)

mysql> insert into cables values ('Genenco VT50', 50, 'firewire', 0);
Query OK, 1 row affected (0.00 sec)

mysql> insert into cables values ('Genenco U100', 100, 'usb', 0);
Query OK, 1 row affected (0.00 sec)

mysql> insert into cables values ('Plexicor uShorty', 20, 'usb', 0);
Query OK, 1 row affected (0.00 sec)

mysql> insert into cables values ('Plexicor fShorty', 20, 'firewire', 0);
Query OK, 1 row affected (0.00 sec)
Now let's take a look at what we've got in the table:
mysql> select * from cables;
+ ------------------+------------ +---------- + --------- +
| name              | lengthInCm  | cableType | cableID   |
+ ------------------+------------ +---------- + --------- +
| Varco DX100       | 100         | firewire  |    1      |
| Genenco VT100     | 100         | firewire  |    2      |
| Genenco VT50      | 50          | firewire  |    3      |
| Genenco U100      | 100         | usb       |    4      |
| Plexicor uShorty  | 20          | usb       |    5      |
| Plexicor fShorty  | 20          | firewire  |    6      |
+ ------------------+------------ +---------- + --------- +
6 rows in set (0.39 sec)

Accessing Your Data from PHP

So now we have a database and a table filled with data. Our next step is to access this data and make it appear on a web page.

As a reminder, your PHP statements will be embedded within your html code. Once your .php file has been handed off to the PHP pre-processor, the pre-processor will interpret the PHP code and replace the code with the output generated by the code. If this confuses you, here's a very short example from last November's column, just to refresh your memory.

Using your plain-text text editor, create a new file called mysqltest.php and save it in your Sites folder, right alongside your test.php file we created earlier. Enter this code in the file and save:

<html>
   <head>
      <title>PHP Test</title>
   </head>
   <body>
      <p>This is some pure HTML loveliness.</p>
      <?php
         echo "<p>Hello, World!</p>\n";
      ?>
      <p>Did we echo properly?</p>
      <?php
         echo date("r");
         echo "\n";
      ?>
      <p>It works!!!</p>
   </body>
</html>

Once your file is saved, go into Safari and enter this address:

http://127.0.0.1/~davemark/mysqltest.php

Make sure you replace "davemark" with your own user name. Figure 2 shows what I saw when my page loaded. The first line was produced by the HTML. The second line was the result of the output of the PHP echo function. The echo function produced some HTML which was added to the stream. Next came another line of HTML ("Did we echo properly?"), followed by another pair of echos, echoing a date string and a return. This is all polished off by a last line of HTML, generating the string "It works!!!".


Figure 2. A simple PHP test.

If you view source on this output, here's what you get:

<html>
   <head>
      <title>PHP Test</title>
   </head>
   <body>
      <p>This is some pure HTML loveliness.</p>
      <p>Hello, World!</p>
      <p>Did we echo properly?</p>
      Wed, 15 Jun 2005 19:43:02 -0400
      <p>It works!!!</p>
   </body>
</html>

Go back and look at the original PHP. Make sure you understand how the original PHP got translated into this source. Remember, every chunk of PHP code in the original source was replaced by its output to achieve this HTML listing.

Connecting to the Database

OK, now we're ready to fetch our data. Our first step is to connect to our database. Open mysqltest.php and replace the contents with this code:

<html>
   <head>
      <title>MySQL Test</title>
   </head>
   <body>
      <p>Connecting to the database...</p>
      <?php
         $host = 'localhost';
         $user = 'root';
         $pw = '';
         $db = 'products';
	
         $link = mysql_connect( $host, $user, $pw )
            or die( 'Could not connect: ' . mysql_error() );
         echo 'Connected successfully';
         mysql_select_db( $db );
      ?>
      <p>If we got here, we've connected!</p>
   </body>
</html>

In the above code, replace the $user and $pw string values with whatever user and password you used to create the database. Save the code and reload this page in Safari: http://127.0.0.1/~davemark/mysqltest.php. Figure 3 shows my results.


Figure 3. Connecting to the database.

In a nutshell, we used the function mysql_connect() to connect to the database and the function mysql_select_db() to select the database. This is like logging in using the MySQL monitor, then saying use products.

One line of code worth taking a second look at is this one:

         $link = mysql_connect( $host, $user, $pw )
            or die( 'Could not connect: ' . mysql_error() );

Notice the use of "or" here. This is a pretty common technique in PHP. The second part of the or clause will only execute if the first part fails. The die() function is equivalent to exit(). die() will post the passed in string as output, then exit.

Notice the use of the "." operator to concatenate two strings together. This is another common PHP technique. In this case, the "." operator will build a single string from 'Could not connect: ' and the string returned by mysql_error(). mysql_error() returns the error message from the previous MySQL operation.

Our next step is to query the database and to print the data we retrieved.

Querying the Database

Back in your text editor, open the file mysqltest.php and replace its contents with this:

<html>
   <head>
      <title>MySQL Test</title>
   </head>
   <body>
      <p>Connecting to the database...</p>
      <?php
         $host = 'localhost';
         $user = 'root';
         $pw = '';
         $db = 'products';

         $link = mysql_connect( $host, $user, $pw )
            or die( 'Could not connect: ' . mysql_error() );
         echo 'Connected successfully';
         mysql_select_db( $db );
      ?>
      <p>Here's the table data:</p>
      <?php
         $sql_statement = "SELECT * FROM cables";
         $results = mysql_query( $sql_statement )
            or printf( "Query error: %s", mysql_error() );

         while ( $row = mysql_fetch_assoc( $results ) )
         {
            echo $row['cableID'] . ": ";
            echo "\"" . $row['name'] . "\"" . ", ";
            echo $row['lengthInCm'] . ", ";
            echo $row['cableType'];
            echo "<p>";
         }
			
         mysql_close( $link );
      ?>
   </body>
</html>

Save the file and reload it from Safari. Figure 4 shows my version of this run. Notice that the data is lightly formatted, with a colon (":") after the item number and commas between each of the fields.


Figure 4. Retrieving the data from the database.

Let's take a look at the code. We started with the original code, connecting to and selecting the database.

<html>
   <head>
      <title>MySQL Test</title>
   </head>
   <body>
      <p>Connecting to the database...</p>
      <?php
         $host = 'localhost';
         $user = 'root';
         $pw = '';
         $db = 'products';

         $link = mysql_connect( $host, $user, $pw )
            or die( 'Could not connect: ' . mysql_error() );
         echo 'Connected successfully';
         mysql_select_db( $db );
      ?>

Next, we spit out a line of HTML, preparing us for the table data to follow.

      <p>Here's the table data:</p>

We load our query into a PHP string, then pass the string into mysql_query(). This is the equivalent of typing the string into the MySQL monitor as a query. Once again, we use the "or" operator and this time, instead of exiting with die(), we'll display an error message using printf(). printf() is derived from its C forbearer, but is a part of the PHP library. As a point of interest, echo is not a function, but is a language construct. You can use echo as a statement, but can't pass it as a function. Use printf() instead.

<?php
         $sql_statement = "SELECT * FROM cables";
         $results = mysql_query( $sql_statement )
            or printf( "Query error: %s", mysql_error() );

Next, we enter a while loop, using mysql_fetch_assoc() to fetch one row of the table at a time. mysql_fetch_assoc() returns an associative array, which is an array indexed by name instead of by number. Instead of $row[3], you'd refer to $row['cableType']. Associative arrays are one of my favorite parts of PHP. Note that you could have also used mysql_fetch_row(), which would have returned a more tradition, numerically indexed array.

while ( $row = mysql_fetch_assoc( $results ) )
         {

For each row of data, we echo the field value, interspersed with colons, spaces and commas. Note that we also make frequent use of the "." operator.

            echo $row['cableID'] . ": ";
            echo "\"" . $row['name'] . "\"" . ", ";
            echo $row['lengthInCm'] . ", ";
            echo $row['cableType'];
            echo "<p>";
         }

Finally, we close the database using the value returned by mysql_connect(), then exit our PHP area and return to HTML.

mysql_close( $link );
      ?>
   </body>
</html>

Until Next Month...

Once again, seems we just get started when I've run out of room to write. <sigh>. Your assignment for this month is to first do a bit of research, then take the result of this month's query and build a nice HTML table instead of just dumping the data using echo. On the research side of things, go to http://php.net and dig down through the PHP manual, looking up the various functions we played with in this month's code. For example, here's a link to the page that talks about mysql_fetch_assoc():

http://php.net/manual/en/function.mysql-fetch-assoc.php

Take some time to get to know the PHP documentation. You'll find it chock full of examples and incredibly useful. Enjoy!


Dave Mark is a long-time Mac developer and author and has written a number of books on Macintosh development. Dave has been writing for MacTech since its birth! Be sure to check out the new Learn C on the Macintosh, Mac OS X Edition at http://www.spiderworks.com.

 

Community Search:
MacTech Search:

Software Updates via MacUpdate

Steam 4.0 - Multiplayer and communicatio...
Steam is a digital distribution, digital rights management, multiplayer and communications platform developed by Valve Corporation. It is used to distribute a large number of games and related media... Read more
OmniGraffle Pro 7.19.3 - Create diagrams...
OmniGraffle Pro helps you draw beautiful diagrams, family trees, flow charts, org charts, layouts, and (mathematically speaking) any other directed or non-directed graphs. We've had people use... Read more
OmniGraffle 7.19.3 - Create diagrams, fl...
OmniGraffle helps you draw beautiful diagrams, family trees, flow charts, org charts, layouts, and (mathematically speaking) any other directed or non-directed graphs. We've had people use Graffle to... Read more
Hopper Disassembler 5.3.3- - Binary disa...
Hopper Disassembler is a binary disassembler, decompiler, and debugger for 32- and 64-bit executables. It will let you disassemble any binary you want, and provide you all the information about its... Read more
calibre 5.35.0 - Complete e-book library...
Calibre is a complete e-book library manager. Organize your collection, convert your books to multiple formats, and sync with all of your devices. Let Calibre be your multi-tasking digital librarian... Read more
Sound Studio 4.10.0 - Robust audio recor...
Sound Studio lets you easily record and professionally edit audio on your Mac. Easily rip vinyls and digitize cassette tapes, or record lectures and voice memos. Prepare for live shows with live... Read more
Sparkle Pro 4.0 - Visual website creator...
Sparkle Pro will change your mind if you thought building websites wasn't for you. Sparkle is the intuitive site builder that lets you create sites for your online portfolio, team or band pages, or... Read more
Dropbox 140.4.1951 - Cloud backup and sy...
Dropbox for Mac is a file hosting service that provides cloud storage, file synchronization, personal cloud, and client software. It is a modern workspace that allows you to get to all of your files... Read more
FotoMagico 6.0.5 - Powerful slideshow cr...
FotoMagico lets you create professional slideshows from your photos and music with just a few, simple mouse clicks. It sports a very clean and intuitive yet powerful user interface. High image... Read more
Remotix 6.4.2 - Access all your computer...
Remotix is a fast and powerful application to easily access multiple Macs (and PCs) from your own Mac. Features: Complete Apple Screen Sharing support - including Mac OS X login, clipboard... Read more

Latest Forum Discussions

See All

A House Full of Covid – The TouchArcade...
It’s been a rough week as both of our young children tested positive for Covid, and since recording this early on Friday my wife has tested positive now too. Thankfully the kids seemed to recover fairly quickly and are mostly back to normal, and I... | Read more »
TouchArcade Game of the Week: ‘Krispee S...
Krispee Street is a new hidden object game from Frosty Pop that is based on their popular and almost painfully sweet webcomic Krispee. This is one of the latest titles to be added to the Netflix Games catalog, which means you’ll need to log into... | Read more »
SwitchArcade Round-Up: ‘Escape Lala’, ‘B...
Hello gentle readers, and welcome to the SwitchArcade Round-Up for January 21st, 2022. In today’s article, we’ve got a lot of new releases. A lot. There were eight on the schedule when I went to bed last night. There were twenty-four when I woke up... | Read more »
Beta Testers Needed for Huge Version 2.0...
Ya’ll remember Dungeon Raid, right? The phenomenal matching RPG hybrid that launched on mobile more than a decade ago, but was more or less abandoned by its developer only to die a slow death on the App Store before the 32-bit Appocalypse finally... | Read more »
‘Ark Legends’ Gives Players a Chance to...
It’s Airpods and Amazon gift cards galore as Melting Games opens pre-registration for Ark Legends. The upcoming mobile RPG is giving away tons of in-game goodies such as gold, energy, iron core, hero summon chest and rare iron core to players who... | Read more »
‘Nickelodeon Extreme Tennis’ Out Now on...
Nickelodeon Extreme Tennis () from Old Skull Games and Nickelodeon is this week’s new Apple Arcade release. Nickelodeon Extreme Tennis features characters from old and new Nickelodeon shows including SpongeBob, TMNT, and many more. The tennis game... | Read more »
SwitchArcade Round-Up: ‘RPGolf Legends’,...
Hello gentle readers, and welcome to the SwitchArcade Round-Up for January 20th, 2022. In today’s article, we’ve got a massive amount of new releases to check out. We’ve got summaries of all of them, from heaven to hell. We also have the lists of... | Read more »
‘Zed Blade ACA NEOGEO’ Review – Well, It...
SNK’s NEOGEO platform played host to a great many classics, both famous and under-the-radar. The Metal Slug games. The King of Fighters series. Magician Lord. Shock Troopers. Sengoku 3. NEO Turf Masters. Fatal Fury. Samurai Shodown. Twinkle Star... | Read more »
‘Inua – A Story in Ice and Time’ is a Un...
One thing I know about ARTE from their output on mobile over the years is that they love collaborating with really interesting and unique studios to put out really interesting and unique gaming experiences. This is true yet again with the latest... | Read more »
Out Now: ‘Angry Birds Journey’, ‘RPG Dic...
Each and every day new mobile games are hitting the App Store, and so each week we put together a big old list of all the best new releases of the past seven days. Back in the day the App Store would showcase the same games for a week, and then... | Read more »

Price Scanner via MacPrices.net

Sunday Sale: Apple AirPods are on sale for up...
Amazon has Apple AirPods on sale for $10-$100 off MSRP today, depending on the model. All are in stock today with free delivery: – AirPods Max headphones (Blue): $449 $100 off MSRP – AirPods Max... Read more
These Apple resellers are offering 13″ M1 Mac...
Apple resellers are offering discounts on 13″ MacBook Pros with M1 Apple Silicon processors ranging up to $150 off MSRP. Here’s where to get one today: (1): Apple’s 13″ MacBook Pros with M1 Apple... Read more
Amazon lowers prices on select 13″ M1 MacBook...
Amazon has select Apple 13″ M1 MacBook Airs on sale for $150 off MSRP this weekend, starting at only $849. Their prices are the lowest available for new MacBook Airs today. Stock may come and go, so... Read more
Apple has 13″ M1 MacBook Airs back in stock s...
Apple has restocked a full line of 13″ M1 MacBook Airs, Certified Refurbished, starting at only $849 and up to $190 off original MSRP. These are the cheapest M1-powered MacBooks for sale today at... Read more
In stock and on sale! 16″ 10-Core M1 Pro MacB...
Amazon has new 16″ 10-Core/512GB M1 Pro MacBook Pros in stock today and on sale for $50 off MSRP including free shipping. Their prices are the lowest available for new M1 Pro 16″ MacBook Pro from any... Read more
Deal Alert!: 14″ M1 Pro with 10-Core CPU in s...
Amazon has the new 14″ M1 Pro MacBook Pro with a 10-Core CPU and 16-Core GPU in stock today and on sale for $2299.99 including free shipping. Their price is $200 off Apple’s standard MSRP, and it’s... Read more
Apple has 24-inch M1 iMacs (8-Core CPU/8-Core...
Apple has restocked a wide array of 24-inch M1 iMacs with 8-Core CPUs and 8-Core GPUs in their Certified Refurbished store. Models are available starting at only $1269 and range up to $260 off... Read more
Select 24″ M1 iMacs are on sale for $100 off...
Sales of Apple’s new 24″ M1 iMacs have been rare since its introduction, perhaps due to global supply issues. However, B&H is offering a $100 discount on select 24″ iMacs, and they’re in stock... Read more
M1 Mac minis are back in stock today at Apple...
Apple has M1-powered Mac minis available in their Certified Refurbished section starting at only $589 and up to $140 off MSRP. Each mini comes with Apple’s one-year warranty, and shipping is free: –... Read more
B&H has M1-powered Mac minis on sale for...
B&H Photo has Apple’s Mac minis with M1 Apple Silicon CPUs in stock today and on sale for $50-$100 off MSRP, starting at $649. Free 1-2 shipping is free to many US addresses. Their prices are... Read more

Jobs Board

Registered Nurse (RN) Employee Health PSJH -...
…is calling for a Registered Nurse (RN) Employee Health PSJH to our location in Apple Valley, CA.** We are seeking a Registered Nurse (RN) Employee Health PSJH to be Read more
Systems Administrator - Pearson (United State...
…and troubleshoot Windows operating systems (workstation and server), laptop computers, Apple iPads, Chromebooks and printers** + **Administer and troubleshoot all Read more
IT Assistant Level 1- IT Desktop Support Anal...
…providing tier-1 or better IT help desk support in a large Windows and Apple environment * Experience using IT Service Desk Management Software * Knowledge of IT Read more
Human Resources Business Partner PSJH - Provi...
…**is calling a** **Human Resources Business Partner, PSJH** **to our location in Apple Valley, CA.** **Applicants that meet qualifications will receive a text with Read more
Manager Community Health Investment Programs...
…is calling a Manager Community Health Investment Programs PSJH to our location in Apple Valley, CA.** **Qualified candidates will be invited to do a self-paced video Read more
All contents are Copyright 1984-2011 by Xplain Corporation. All rights reserved. Theme designed by Icreon.