Difference between revisions of "PHP199"

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== Install MySQL & PHP on Windows==
 +
 +
If students require to install PHP & MYSQL on windows platform please email me at R.Kabul@wlv.ac.uk i will provide you with the required details.
 +
 +
== WAMP ==
 +
 +
If you are having problem installing PHP, Apache and MySQL, use WAMP. WAMP stands for Windows, Apache, MySQL and PHP. It is a single application that consists PHP, Apache and MySQL in a bundle.
 +
 +
The link: http://www.wampserver.com
 +
 +
All you have to do is download the WAMP5 installation file and install it. No hassle at all. Cheers!!
 +
 +
== Using mysql_num_rows() ==
 +
 +
This is a small tip I haven't seen on the Wiki which shows you how to print correct statements depending on the number of rows return from your MySQL queries.  The function '''mysql_num_rows()''' is the one to look for.
 +
 +
''Example''
 +
 +
<pre>
 +
<?php
 +
// Database connection here...
 +
 +
$sql = "SELECT title,author FROM comics';
 +
 +
$res = mysql_query($sql);
 +
 +
// An error occurred!
 +
if (!$res) {
 +
  echo mysql_error();
 +
}
 +
 +
$total = mysql_num_rows($res);
 +
 +
if ($total == 0) {
 +
  echo 'No rows were returned';
 +
} elseif ($total == 1) {
 +
  echo '1 row was returned';
 +
} else {
 +
  echo $total . ' rows were returned';
 +
}
 +
?>
 +
</pre>
 +
 
== Viewing contents of array ==
 
== Viewing contents of array ==
  
 
A good tip for checking the information returned from the database is to use &lt;pre&gt; and print_r() which outputs arrays in a more readable form...
 
A good tip for checking the information returned from the database is to use &lt;pre&gt; and print_r() which outputs arrays in a more readable form...
  
−
e.g.
+
''Example''
  
 
Presuming the following SQL was used on the comics database...<br />
 
Presuming the following SQL was used on the comics database...<br />
Line 10: Line 53:
 
This would return the title and author details for the first record in the table.
 
This would return the title and author details for the first record in the table.
  
−
If you then used mysql_fetch_array() to get the first record and output it's contents wrapped in &lt;pre&gt; you get a nicely formatted view of the array and it's contents.
+
If you then used mysql_fetch_array() to return the details as an array and output it's contents wrapped in &lt;pre&gt; you get a nicely formatted view of the array and it's contents.
  
 
<pre>
 
<pre>
−
<?
+
<?php
 
// Database connection here...
 
// Database connection here...
  
Line 19: Line 62:
  
 
$res = mysql_query($sql);
 
$res = mysql_query($sql);
 +
 +
// An error occurred!
 +
if (!$res) {
 +
  echo mysql_error();
 +
}
  
 
$row = mysql_fetch_assoc($res);
 
$row = mysql_fetch_assoc($res);
Line 36: Line 84:
 
</pre>
 
</pre>
  
−
Can be especially useful when using multidimensional arrays, or when you have alot of fields returned from the database.
+
Can be especially useful when using multidimensional arrays, or when you have a lot of fields returned from the database.
 +
 
 +
''Multidimensional Array Example''<br>
 +
 
 +
Using the earlier example of planets, this is how the $planet2 array would look using this method...
 +
 
 +
<pre>
 +
<?php
 +
      $planets2 = array
 +
      (
 +
        "Mercury"=> array("dist"=>0.39, "dia"=>0.38),
 +
        "Venus"  => array("dist"=>0.39, "dia"=>0.95),
 +
        "Earth"  => array("dist"=>1.0,  "dia"=>1.0, "moons"=>array("Moon")),
 +
        "Mars"  => array("dist"=>0.39, "dia"=>0.53, "moons"=>array("Phobos", "Deimos"))
 +
      );
 +
      echo '&lt;pre&gt;'; print_r($planets2); echo '&lt;/pre&gt;';
 +
?>
 +
</pre>
 +
 
 +
Would print...
 +
 
 +
<pre>
 +
Array
 +
(
 +
    [Mercury] => Array
 +
        (
 +
            [dist] => 0.39
 +
            [dia] => 0.38
 +
        )
 +
 
 +
    [Venus] => Array
 +
        (
 +
            [dist] => 0.39
 +
            [dia] => 0.95
 +
        )
 +
 
 +
    [Earth] => Array
 +
        (
 +
            [dist] => 1
 +
            [dia] => 1
 +
            [moons] => Array
 +
                (
 +
                    [0] => Moon
 +
                )
 +
 
 +
        )
 +
 
 +
    [Mars] => Array
 +
        (
 +
            [dist] => 0.39
 +
            [dia] => 0.53
 +
            [moons] => Array
 +
                (
 +
                    [0] => Phobos
 +
                    [1] => Deimos
 +
                )
 +
 
 +
        )
 +
 
 +
)
 +
</pre>

Latest revision as of 18:13, 19 February 2007

Install MySQL & PHP on Windows

If students require to install PHP & MYSQL on windows platform please email me at R.Kabul@wlv.ac.uk i will provide you with the required details.

WAMP

If you are having problem installing PHP, Apache and MySQL, use WAMP. WAMP stands for Windows, Apache, MySQL and PHP. It is a single application that consists PHP, Apache and MySQL in a bundle.

The link: http://www.wampserver.com

All you have to do is download the WAMP5 installation file and install it. No hassle at all. Cheers!!

Using mysql_num_rows()

This is a small tip I haven't seen on the Wiki which shows you how to print correct statements depending on the number of rows return from your MySQL queries. The function mysql_num_rows() is the one to look for.

Example 

<?php
// Database connection here...

$sql = "SELECT title,author FROM comics';

$res = mysql_query($sql);

// An error occurred!
if (!$res) {
  echo mysql_error();
}

$total = mysql_num_rows($res);

if ($total == 0) {
  echo 'No rows were returned';
} elseif ($total == 1) {
  echo '1 row was returned';
} else {
  echo $total . ' rows were returned';
}
?>

Viewing contents of array

A good tip for checking the information returned from the database is to use <pre> and print_r() which outputs arrays in a more readable form...

Example

Presuming the following SQL was used on the comics database...

SELECT title,author FROM comics LIMIT 1

This would return the title and author details for the first record in the table.

If you then used mysql_fetch_array() to return the details as an array and output it's contents wrapped in <pre> you get a nicely formatted view of the array and it's contents. 

<?php
// Database connection here...

$sql = "SELECT title,author FROM comics LIMIT 1';

$res = mysql_query($sql);

// An error occurred!
if (!$res) {
  echo mysql_error();
}

$row = mysql_fetch_assoc($res);

echo '<pre>'; print_r($row); echo '<pre>';

?>

Would print the following... 

Array
(
    [title] => Elfquest
    [author] => Richard/Pini (Wendi)
)

Can be especially useful when using multidimensional arrays, or when you have a lot of fields returned from the database.

Multidimensional Array Example

Using the earlier example of planets, this is how the $planet2 array would look using this method... 

<?php
       $planets2 = array
       (
         "Mercury"=> array("dist"=>0.39, "dia"=>0.38),
         "Venus"  => array("dist"=>0.39, "dia"=>0.95),
         "Earth"  => array("dist"=>1.0,  "dia"=>1.0, "moons"=>array("Moon")),
         "Mars"   => array("dist"=>0.39, "dia"=>0.53, "moons"=>array("Phobos", "Deimos"))
       );
       echo '<pre>'; print_r($planets2); echo '</pre>';
?>

Would print... 

Array
(
    [Mercury] => Array
        (
            [dist] => 0.39
            [dia] => 0.38
        )

    [Venus] => Array
        (
            [dist] => 0.39
            [dia] => 0.95
        )

    [Earth] => Array
        (
            [dist] => 1
            [dia] => 1
            [moons] => Array
                (
                    [0] => Moon
                )

        )

    [Mars] => Array
        (
            [dist] => 0.39
            [dia] => 0.53
            [moons] => Array
                (
                    [0] => Phobos
                    [1] => Deimos
                )

        )

)
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