DataTables server-side processing example

# Preamble

There are many ways to get your data into DataTables, and if you are working with seriously large databases, you might want to consider using the server-side options that DataTables provides. Basically all of the paging, filtering, sorting etc that DataTables does can be handed off to a server (or any other data source - Google Gears or Adobe Air for example!) and DataTables is just an events and display module.

The example here shows a very simple display of the CSS data (used in all my other examples), but in this instance coming from the server on each draw. Filtering, multi-column sorting etc all work as you would expect.

# Live example

Rendering engine | Browser | Platform(s) | Engine version | CSS grade
--- | --- | --- | --- | ---
Loading data from server
Rendering engine | Browser | Platform(s) | Engine version | CSS grade

# Initialisation code

    $(document).ready(function() {
    	$('#example').dataTable( {
    		"bProcessing": true,
    		"bServerSide": true,
    		"sAjaxSource": "scripts/server_processing.php"
    	} );
    } );

# Server response

The code below shows the latest JSON data that has been returned from the server in response to the Ajax request made by DataTables. This will update as further requests are made.

# Server side (PHP) code

    <?php
    	/* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *
    	 * Easy set variables
    	 */

    	/* Array of database columns which should be read and sent back to DataTables. Use a space where
    	 * you want to insert a non-database field (for example a counter or static image)
    	 */
    	$aColumns = array( 'engine', 'browser', 'platform', 'version', 'grade' );

    	/* Indexed column (used for fast and accurate table cardinality) */
    	$sIndexColumn = "id";

    	/* DB table to use */
    	$sTable = "ajax";

    	/* Database connection information */
    	$gaSql['user']       = "";
    	$gaSql['password']   = "";
    	$gaSql['db']         = "";
    	$gaSql['server']     = "localhost";

    	/* REMOVE THIS LINE (it just includes my SQL connection user/pass) */
    	include( $_SERVER['DOCUMENT_ROOT']."/datatables/mysql.php" );

    	/* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *
    	 * If you just want to use the basic configuration for DataTables with PHP server-side, there is
    	 * no need to edit below this line
    	 */

    	/*
    	 * Local functions
    	 */
    	function fatal_error ( $sErrorMessage = '' )
    	{
    		header( $_SERVER['SERVER_PROTOCOL'] .' 500 Internal Server Error' );
    		die( $sErrorMessage );
    	}

    	/*
    	 * MySQL connection
    	 */
    	if ( ! $gaSql['link'] = mysql_pconnect( $gaSql['server'], $gaSql['user'], $gaSql['password']  ) )
    	{
    		fatal_error( 'Could not open connection to server' );
    	}

    	if ( ! mysql_select_db( $gaSql['db'], $gaSql['link'] ) )
    	{
    		fatal_error( 'Could not select database ' );
    	}

    	/*
    	 * Paging
    	 */
    	$sLimit = "";
    	if ( isset( $_GET['iDisplayStart'] ) && $_GET['iDisplayLength'] != '-1' )
    	{
    		$sLimit = "LIMIT ".mysql_real_escape_string( $_GET['iDisplayStart'] ).", ".
    			mysql_real_escape_string( $_GET['iDisplayLength'] );
    	}

    	/*
    	 * Ordering
    	 */
    	$sOrder = "";
    	if ( isset( $_GET['iSortCol_0'] ) )
    	{
    		$sOrder = "ORDER BY  ";
    		for ( $i=0 ; $i<intval( $_GET['iSortingCols'] ) ; $i++ )
    		{
    			if ( $_GET[ 'bSortable_'.intval($_GET['iSortCol_'.$i]) ] == "true" )
    			{
    				$sOrder .= "`".$aColumns[ intval( $_GET['iSortCol_'.$i] ) ]."` ".
    				 	mysql_real_escape_string( $_GET['sSortDir_'.$i] ) .", ";
    			}
    		}

    		$sOrder = substr_replace( $sOrder, "", -2 );
    		if ( $sOrder == "ORDER BY" )
    		{
    			$sOrder = "";
    		}
    	}

    	/*
    	 * Filtering
    	 * NOTE this does not match the built-in DataTables filtering which does it
    	 * word by word on any field. It's possible to do here, but concerned about efficiency
    	 * on very large tables, and MySQL's regex functionality is very limited
    	 */
    	$sWhere = "";
    	if ( isset($_GET['sSearch']) && $_GET['sSearch'] != "" )
    	{
    		$sWhere = "WHERE (";
    		for ( $i=0 ; $i<count($aColumns) ; $i++ )
    		{
    			$sWhere .= "`".$aColumns[$i]."` LIKE '%".mysql_real_escape_string( $_GET['sSearch'] )."%' OR ";
    		}
    		$sWhere = substr_replace( $sWhere, "", -3 );
    		$sWhere .= ')';
    	}

    	/* Individual column filtering */
    	for ( $i=0 ; $i<count($aColumns) ; $i++ )
    	{
    		if ( isset($_GET['bSearchable_'.$i]) && $_GET['bSearchable_'.$i] == "true" && $_GET['sSearch_'.$i] != '' )
    		{
    			if ( $sWhere == "" )
    			{
    				$sWhere = "WHERE ";
    			}
    			else
    			{
    				$sWhere .= " AND ";
    			}
    			$sWhere .= "`".$aColumns[$i]."` LIKE '%".mysql_real_escape_string($_GET['sSearch_'.$i])."%' ";
    		}
    	}

    	/*
    	 * SQL queries
    	 * Get data to display
    	 */
    	$sQuery = "
    		SELECT SQL_CALC_FOUND_ROWS `".str_replace(" , ", " ", implode("`, `", $aColumns))."`
    		FROM   $sTable
    		$sWhere
    		$sOrder
    		$sLimit
    		";
    	$rResult = mysql_query( $sQuery, $gaSql['link'] ) or fatal_error( 'MySQL Error: ' . mysql_errno() );

    	/* Data set length after filtering */
    	$sQuery = "
    		SELECT FOUND_ROWS()
    	";
    	$rResultFilterTotal = mysql_query( $sQuery, $gaSql['link'] ) or fatal_error( 'MySQL Error: ' . mysql_errno() );
    	$aResultFilterTotal = mysql_fetch_array($rResultFilterTotal);
    	$iFilteredTotal = $aResultFilterTotal[0];

    	/* Total data set length */
    	$sQuery = "
    		SELECT COUNT(`".$sIndexColumn."`)
    		FROM   $sTable
    	";
    	$rResultTotal = mysql_query( $sQuery, $gaSql['link'] ) or fatal_error( 'MySQL Error: ' . mysql_errno() );
    	$aResultTotal = mysql_fetch_array($rResultTotal);
    	$iTotal = $aResultTotal[0];

    	/*
    	 * Output
    	 */
    	$output = array(
    		"sEcho" => intval($_GET['sEcho']),
    		"iTotalRecords" => $iTotal,
    		"iTotalDisplayRecords" => $iFilteredTotal,
    		"aaData" => array()
    	);

    	while ( $aRow = mysql_fetch_array( $rResult ) )
    	{
    		$row = array();
    		for ( $i=0 ; $i<count($aColumns) ; $i++ )
    		{
    			if ( $aColumns[$i] == "version" )
    			{
    				/* Special output formatting for 'version' column */
    				$row[] = ($aRow[ $aColumns[$i] ]=="0") ? '-' : $aRow[ $aColumns[$i] ];
    			}
    			else if ( $aColumns[$i] != ' ' )
    			{
    				/* General output */
    				$row[] = $aRow[ $aColumns[$i] ];
    			}
    		}
    		$output['aaData'][] = $row;
    	}

    	echo json_encode( $output );
    ?>

# Other examples

## Basic initialisation

- Zero configuration
- Feature enablement
- Sorting data
- Multi-column sorting
- Multiple tables
- Hidden columns
- Complex headers - grouping with colspan
- DOM positioning
- Flexible table width
- State saving
- Alternative pagination styles
- Scrolling:
  Horizontal / Vertical / Both / Themed / Infinite
- Change language information (internationalisation)
- ThemeRoller themes (Smoothness)

## Advanced initialisation

- Events:
  Live events / Pre-init / Post-init
- Column rendering
- Sorting without HTML tags
- Multiple table controls (sDom)
- Defining length menu options
- Complex headers and hidden columns
- Custom toolbar (element) around table
- Row highlighting with CSS
- Row grouping
- Row callback
- Footer callback
- Control sorting direction of columns
- Change language information from a file (internationalisation)
- Setting defaults
- State saving with localStorage
- Custom events

## API

- Dynamically add a new row
- Individual column filtering (using "input" elements)
- Individual column filtering (using "select" elements)
- Highlight rows and columns
- Show and hide details about a particular record
- User selectable rows (multiple rows)
- User selectable rows (single row) and delete rows
- Editable rows (with jEditable)
- Submit form with elements in table
- Index column (static number column)
- Show and hide columns dynamically
- API function use in initialisation object (callback)
- DataTables scrolling and tabs
- Regular expression filtering

## Data sources

- DOM
- Javascript array
- Ajax source
- Server side processing

## Server-side processing

- Obtain server-side data
- Add extra HTTP variables
- Use HTTP POST
- Automatic addition of IDs and classes to rows
- Reading table data from objects
- Show and hide details about a particular record
- User selectable rows (multiple rows)
- JSONP for a cross domain data source
- jEditable integration with DataTables
- Deferred loading of Ajax data
- Pipelining data (reduce Ajax calls for paging)

## Ajax data source

- Ajax sourced data (array of arrays)
- Ajax sourced data (array of objects)
- Deferred DOM creation for extra speed
- Empty data source columns
- Use a data source other than aaData (the default)
- Read column data from sub-arrays
- Read column data from deeply nested properties

## Plug-ins

- Add custom API functions
- Sorting and automatic type detection
- Sorting without automatic type detection
- Custom pagination controls
- Range filtering / custom filtering
- Live DOM sorting
- Automatic HTML type detection