Datatables serverside processing using mysqli json - php

Question

I am using datatables without a problem, but some pages crash due to the large amount of data that it's fetching from the database. So I tried to implement server side processing. I followed the examples on the site, but I just don't seem to receive the json data sent from the php file. Can someone please tell me what's wrong?
What I get on console is: jquery.min.js:5 POST http://example.com//datatables-script.php net::ERR_EMPTY_RESPONSE.
Response at Network tab says: Failed to load response data
This is my ajax call:
$(document).ready(function(){
$('#sort').dataTable({
"ajax": {
url: "datatables-script.php",
type: "POST",
data: {storeid:'<?php echo $stid; ?>'},
//dataType: 'json',
success: function(gotback) {
//var JSONArray = JSON.stringify(data);
//console.log(JSONArray);
console.log(gotback);
}
},
"processing": true,
"serverSide": true,
"bServerSide": true,
});
This is my script: Sorry for the long post.
<?php
mb_internal_encoding('UTF-8');
$aColumns = array( 'Rec_Id', 'Br_Id', 'C_Id', 'SubcId', 'ProdId', 'Prodme', 'URL', 'Im0', 'Price' );
$sIndexColumn = 'Rec_Id';
$sTable = 'tb';
$gaSql['user'] = 'ss';
$gaSql['password'] = 'sss';
$gaSql['db'] = 's';
$gaSql['server'] = 's';
$gaSql['port'] = 3306; // 3306 is the default MySQL port
// Input method (use $_GET, $_POST or $_REQUEST)
$input =& $_POST;
$gaSql['charset'] = 'utf8';
//get store id
$storeid = $_POST['storeid'];
$db = new mysqli($gaSql['server'], $gaSql['user'], $gaSql['password'], $gaSql['db'], $gaSql['port']);
if (mysqli_connect_error()) {
die( 'Error connecting to MySQL server (' . mysqli_connect_errno() .') '. mysqli_connect_error() );
}
if (!$db->set_charset($gaSql['charset'])) {
die( 'Error loading character set "'.$gaSql['charset'].'": '.$db->error );
}
$sLimit = "";
if ( isset( $input['iDisplayStart'] ) && $input['iDisplayLength'] != '-1' ) {
$sLimit = " LIMIT ".intval( $input['iDisplayStart'] ).", ".intval( $input['iDisplayLength'] );
}
$aOrderingRules = array();
if ( isset( $input['iSortCol_0'] ) ) {
$iSortingCols = intval( $input['iSortingCols'] );
for ( $i=0 ; $i<$iSortingCols ; $i++ ) {
if ( $input[ 'bSortable_'.intval($input['iSortCol_'.$i]) ] == 'true' ) {
$aOrderingRules[] =
"".$aColumns[ intval( $input['iSortCol_'.$i] ) ]." "
.($input['sSortDir_'.$i]==='asc' ? 'asc' : 'desc');
}
}
}
if (!empty($aOrderingRules)) {
$sOrder = " ORDER BY ".implode(", ", $aOrderingRules);
} else {
$sOrder = "";
}
$iColumnCount = count($aColumns);
if ( isset($input['sSearch']) && $input['sSearch'] != "" ) {
$aFilteringRules = array();
for ( $i=0 ; $i<$iColumnCount ; $i++ ) {
if ( isset($input['bSearchable_'.$i]) && $input['bSearchable_'.$i] == 'true' ) {
$aFilteringRules[] = "".$aColumns[$i]." LIKE '%".$db->real_escape_string( $input['sSearch'] )."%'";
}
}
if (!empty($aFilteringRules)) {
$aFilteringRules = array('('.implode(" OR ", $aFilteringRules).')');
}
}
// Individual column filtering
for ( $i=0 ; $i<$iColumnCount ; $i++ ) {
if ( isset($input['bSearchable_'.$i]) && $input['bSearchable_'.$i] == 'true' && $input['sSearch_'.$i] != '' ) {
$aFilteringRules[] = "".$aColumns[$i]." LIKE '%".$db->real_escape_string($input['sSearch_'.$i])."%'";
}
}
if (!empty($aFilteringRules)) {
$sWhere = " WHERE sid=$storeid ".implode(" AND ", $aFilteringRules);
} else {
$sWhere = "";
$aQueryColumns = array();
foreach ($aColumns as $col) {
if ($col != ' ') {
$aQueryColumns[] = $col;
}
}
$sQuery = "
SELECT SQL_CALC_FOUND_ROWS ".implode(", ", $aQueryColumns)."
FROM ".$sTable."".$sWhere.$sOrder.$sLimit;
//echo $sQuery;
$rResult = $db->query( $sQuery ) or die($db->error);
// Data set length after filtering
$sQuery = "SELECT FOUND_ROWS()";
$rResultFilterTotal = $db->query( $sQuery ) or die($db->error);
list($iFilteredTotal) = $rResultFilterTotal->fetch_row();
// Total data set length
$sQuery = "SELECT COUNT(".$sIndexColumn.") FROM ".$sTable."";
$rResultTotal = $db->query( $sQuery ) or die($db->error);
list($iTotal) = $rResultTotal->fetch_row();
$output = array(
"sEcho" => intval($input['sEcho']),
"iTotalRecords" => $iTotal,
"iTotalDisplayRecords" => $iFilteredTotal,
"aaData" => array(),
);
while ( $aRow = $rResult->fetch_assoc() ) {
$row = array();
for ( $i=0 ; $i<$iColumnCount ; $i++ ) {
if ( $aColumns[$i] == 'version' ) {
// Special output formatting for 'version' column
$row[] = ($aRow[ $aColumns[$i] ]=='0') ? '-' : $aRow[ $aColumns[$i] ];
} elseif ( $aColumns[$i] != ' ' ) {
// General output
$row[] = $aRow[ $aColumns[$i] ];
}
}
$output['aaData'][] = $row;
}
echo json_encode( $output );

Answer 1

Check this example, I am using the same in my project:
JS:
$('#datatable_location_details').dataTable({
"sServerMethod": "GET",
"bProcessing": true,
"bServerSide": true,
"sAjaxSource": "getdetails.php,
// "aoColumns": [null, null, null, null, { "bSortable": true, "sClass": "align_center" }, { "bSortable": true, "sClass": "align_center" }, { "bSortable": false, "sClass": "align_center" }]
});
Php:
$start = $_REQUEST['iDisplayStart'];
$length = $_REQUEST['iDisplayLength'];
$col = $_REQUEST['iSortCol_0'];
$arr = array(0 => 'state', 1 => 'city', 2 => 'institute_name', 3 => 'address', 4 => 'student_count', 5 => 'ranking');
$sort_by = $arr[$col];
$sort_type = $_REQUEST['sSortDir_0'];
$qry = "select id, institute_name, address, state, city, student_count, ranking, latitude, longitude from location_details where (state LIKE '%".$state."%' and city LIKE '%".$city."%' and institute_name LIKE '%".$name."%' and address LIKE '%".$address."%') and (address != '' and state != '' and city != '') ORDER BY ".$sort_by." ".$sort_type." LIMIT ".$start.", ".$length;
$res = mysqli_query($con, $qry);
while($row = mysqli_fetch_assoc($res))
{
$data[] = $row;
}
$qry = "select count(id) as count from location_details";
$res = mysqli_query($con, $qry);
while($row = mysqli_fetch_assoc($res))
{
$iTotal = $row['count'];
}
$rec = array(
'iTotalRecords' => $iTotal,
'iTotalDisplayRecords' => $iTotal,
'aaData' => array()
);
$k=0;
if (isset($data) && is_array($data))
{
foreach ($data as $item)
{
$action = 'Show Map';
$tooltip= 'Show Map';
$class = 'show_details';
if($item['latitude'] == '' && $item['longitude'] == '')
{
$action = 'Modify Address';
$tooltip= 'Latitude & Longitude are not available for this address';
$class = 'modify_address';
}
$rec['aaData'][$k] = array(
0 => $item['state'],
1 => $item['city'],
2 => htmlspecialchars($item['institute_name'], ENT_QUOTES),
3 => htmlspecialchars($item['address'], ENT_QUOTES),
4 => $item['student_count'],
5 => $item['ranking'],
6 => ''.$action.'',
);
$k++;
}
}
echo json_encode($rec);
For more info check this Github Project