Bright Cherry » MySQL & PHP

MySQL / PHP – Optimize MySQL Tables Script

adm1n — Fri, 22 Apr 2011 09:44:25 +0000

The MySQL Optimize Table command will effectively de-fragment a mysql table; it’s useful for tables which are frequently updated and/or rows are deleted. Optimizing will will help with overall performance.

I’ve quickly written a PHP script that optimizes all MySQL tables in a chosen Database. All you need to do is fill in the correct DB settings, run the PHP script, and all the tables will be optimized. The script will also return the results in the following format:

PHP/MySQL code


//db connection details
$host = "localhost";
$username = "root";
$password = "";
$db = "wordpress";
 
//connect to db
$db_connection = mysql_connect($host, $username, $password) or die("Could not connect to db");
mysql_select_db ($db, $db_connection) or die("Could not connect to table");
 
//get statuses for tables in db
$sql = "SHOW TABLE STATUS";
$result	= mysql_query($sql);
 
//initialize array
$tables = array();
while($row = mysql_fetch_array($result))
{
    // return the size in Kilobytes
    $table_size = ($row[ "Data_length" ] + $row[ "Index_length" ]) / 1024;
    $tables[$row['Name']] = sprintf("%.2f", $table_size);
 
    //get total size of all tables
    $total_size += round($table_size,2);
 
    // optimize tables
    $optimise_sql = "OPTIMIZE TABLE {$row['Name']}";
    $optimise_result = mysql_query($optimise_sql);
}
 
//get statuses for tables in db after optimization
$sql = "SHOW TABLE STATUS";
 
//initialize array
$optimised_tables = array();
$result	= mysql_query($sql);
while($row = mysql_fetch_array($result))
{
	// return the size in Kilobytes
	$table_size = ($row[ "Data_length" ] + $row[ "Index_length" ]) / 1024;
	$optimised_tables[$row['Name']] = sprintf("%.2f", $table_size);
 
	//get total size of all tables after optimization
	$optimise_total_size += round($table_size,2);
}
?>

Code to output results

<table width="600" border="1">
	<thead>
		<tr>
			<th>Tableth>
			<th>Size (KB)th>
			<th>Optimised Size (KB)th>
			<th>Optimisedth>
		tr>
	thead>
	<tbody>
	foreach($tables as $table => $size):?>
	<tr>
		<td>$table;?>td>
		<td>$size;?>td>
		<td>$optimised_tables[$table];?>td>
		<td>
			if($size > $optimised_tables[$table]):?>
				$size - $optimised_tables[$table];?>
			endif;?>
		td>
	tr>
	endforeach;?>
	<tr>
		<td><b>Totalb>td>
		<td><b>$total_size;?>b>td>
		<td><b>$optimise_total_size;?>b>td>
		<td><b>round($total_size - $optimise_total_size,2);?>b>td>
	tr>
	tbody>
table>

Download

Download MySQL / PHP – Optimize MySQL Tables Script

PHP / MySQL – Strip Content And Only Display Images From A MySQL Table

adm1n — Sun, 20 Jun 2010 20:56:10 +0000

This is another one of those quite specific pieces of code, so I doubt many people will need it. I think the code is quite useful, so I thought i’d make a post about it. Anyways, I’m going to show you how you can pull just images out of a field in a MySQL table. I used this code yesterday, to specifically pull out all images from a WordPress Blog – to look at all the images that have been posted in ALL articles.

What the following PHP/MySQL code will specifcally deliver…

It will pull out ONLY images
If one field has multiple images, it will display ALL of them

//this query will only get the rows that have images in them
$sql =
"SELECT [field]
FROM [table]
WHERE [field] LIKE '%;
//execute the query
$result = mysql_query($sql);
//loop the results
while($row = mysql_fetch_array($result))
{
 //this is the magic - preg_match matches all the images saves them into an array called images[]
 preg_match_all('/]+>/i',$row['ENTER FIELD'],$images[]);
}
 
//echo out all the images
print_r($images);

That’s it! The print_r will show you all the images when you load the page. The preg_match_all line can actually be used with any string to pull out image references (or whatever regulat expression you require). I’m just specifcially demonstrating how I used it with WordPress/images.

If you don’t want to see the images, and just want to see the actual image URL’s, you can do the following…

//put the images[] array into a foreach loop
foreach($images as $image)
{
  //because each entry may have multiple images, we have to loop through each row to get each image
  foreach($image[0] as $img)
  {
    //remove the  tag
    $img = str_replace(','', $img);
    //explode each image by double quotes (or single quotes depending on how you quote your images), so we know where the image URL ends!
    $img = explode('" ', $img);
    //rename the image URL to $file for ease
    $file = $img[0];
   //echo out each image URL
    echo $file . "
";;
  }
}

Please let mw know if anyone actually uses this code and how useful it was…

PHP/MySQL- Escape All POST Or GET Variables For MySQL INSERT

adm1n — Tue, 16 Feb 2010 19:26:58 +0000

I’m quickly going to demonstrate how to escape special characters in a string for all POST/GET variables safe for a MySQL INSERT query when passing values from a HTML form.

So, let’s say we have a form like this on index.php:



Details

First Name:





Surname:





Email:

The form’s action is insert.php, so whichever method you choose (GET/POST) will get passed to insert.php. Now, before you INSERT the data into a MySQL table, you should ensure the data is safe to INSERT.

The PHP function you should use is mysql_real_escape_string.

You can do the following before inserting the data (assuming the method type is POST):

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$_POST['first_name'] = mysql_real_escape_string($_POST['first_name']);
$_POST['surname'] = mysql_real_escape_string($_POST['surname']);
$_POST['email'] = mysql_real_escape_string($_POST['email']);

But that’s not a very efficient method because you’re repeating the same function over and over, and if the form you’re using has a lot more fields, it will quickly become very problematic for a number of reasons.

Here’s a better and more efficient way of cleaning the data:

foreach(array_keys($_POST) as $key)
{
  $clean[$key] = mysql_real_escape_string($_POST[$key]);
}

So what’s happening now is that ALL the POST variables are being cleaned in the foreach loop. You’re also renaming the POST values to $clean, but keeping the actual key value the same – so to echo the values you simply do this:

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echo $clean['first_name'];
echo $clean['surname'];
echo $clean['email'];

It’s as easy as that

MySQL & PHP- Show Tables In Database

adm1n — Fri, 14 Nov 2008 09:01:00 +0000

Someone asked me the other day how to display the existing tables in their database with a PHP script. The query itself is pretty simple, but people seem to get confused about the PHP side of it. Then again, once you look at the code, you might be surprised how easy it really is…

Printing tables with PHP


$showtablequery = "
	SHOW TABLES
	FROM
	[database]
	";
 
$showtablequery_result	= mysql_query($showtablequery);
while($showtablerow = mysql_fetch_array($showtablequery_result))
{
	echo $showtablerow[0]."
";
}
 
?>

That query will show ALL tables, but you can use a LIKE function in the query as well, to get particular tables only.

Printing particular tables with PHP


$showtablequery = "
	SHOW TABLES
	FROM
	[database]
	LIKE
	'%brightcherry%'
	";
 
$showtablequery_result	= mysql_query($showtablequery);
while($showtablerow = mysql_fetch_array($showtablequery_result))
{
	echo $showtablerow[0]."
";
}
 
?>

That query will pull out all tables with the word ‘brightcherry’ in.