$(document).ready(function() {
    $('#example').dataTable( {
        "processing": true,
        "serverSide": true,
        "ajax": "../resources/server_processing_custom.php"
    } );
} );

<table id="example" class="display" cellspacing="0" width="100%">
        <thead>
            <tr>
                <th>First name</th>
                <th>Last name</th>
                <th>Position</th>
                <th>Office</th>
                <th>Start date</th>
                <th>Salary</th>
            </tr>
        </thead>

        <tfoot>
            <tr>
                <th>First name</th>
                <th>Last name</th>
                <th>Position</th>
                <th>Office</th>
                <th>Start date</th>
                <th>Salary</th>
            </tr>
        </tfoot>
    </table>

F12查看NetWork里name为server_processing_custom.php的请求和返回

<?php
/**
 * Created by PhpStorm.
 * User: dt.thxopen.com
 * Date: 2014/12/7
 * Time: 11:13
 */
try {
    //连接数据库
    $db = new SQLite3('datatables.sqlite3');
} catch (PDOException $e) {
    fatal(
        "数据库连接出错" . $e->getMessage()
    );
}

//获取Datatables发送的参数 必要
$draw = $_GET['draw'];//这个值作者会直接返回给前台

//排序
$order_column = $_GET['order']['0']['column'];//那一列排序，从0开始
$order_dir = $_GET['order']['0']['dir'];//ase desc 升序或者降序

//拼接排序sql
$orderSql = "";
if(isset($order_column)){
    $i = intval($order_column);
    switch($i){
        case 0;$orderSql = " order by first_name ".$order_dir;break;
        case 1;$orderSql = " order by last_name ".$order_dir;break;
        case 2;$orderSql = " order by position ".$order_dir;break;
        case 3;$orderSql = " order by office ".$order_dir;break;
        case 4;$orderSql = " order by start_date ".$order_dir;break;
        case 5;$orderSql = " order by salary ".$order_dir;break;
        default;$orderSql = '';
    }
}
//搜索
$search = $_GET['search']['value'];//获取前台传过来的过滤条件

//分页
$start = $_GET['start'];//从多少开始
$length = $_GET['length'];//数据长度
$limitSql = '';
$limitFlag = isset($_GET['start']) && $length != -1 ;
if ($limitFlag ) {
    $limitSql = " LIMIT ".intval($start).", ".intval($length);
}

//定义查询数据总记录数sql
$sumSql = "SELECT count(id) as sum FROM DATATABLES_DEMO";
//条件过滤后记录数 必要
$recordsFiltered = 0;
//表的总记录数 必要
$recordsTotal = 0;
$recordsTotalResult = $db->query($sumSql);
while ($row = $recordsTotalResult->fetchArray(SQLITE3_ASSOC)) {
    $recordsTotal =  $row['sum'];
}
//定义过滤条件查询过滤后的记录数sql
$sumSqlWhere =" where first_name||last_name||position||office||start_date||salary LIKE '%".$search."%'";
if(strlen($search)>0){
    $recordsFilteredResult = $db->query($sumSql.$sumSqlWhere);
    while ($row = $recordsFilteredResult->fetchArray(SQLITE3_ASSOC)) {
        $recordsFiltered =  $row['sum'];
    }
}else{
    $recordsFiltered = $recordsTotal;
}

//query data
$totalResultSql = "SELECT first_name,last_name,position,office,start_date,salary FROM DATATABLES_DEMO";
$infos = array();
if(strlen($search)>0){
    //如果有搜索条件，按条件过滤找出记录
    $dataResult = $db->query($totalResultSql.$sumSqlWhere.$orderSql.$limitSql);
    while ($row = $dataResult->fetchArray(SQLITE3_ASSOC)) {
        $obj = array($row['first_name'], $row['last_name'], $row['position'], $row['office'], $row['start_date'], $row['salary']);
        array_push($infos,$obj);
    }
}else{
    //直接查询所有记录
    $dataResult = $db->query($totalResultSql.$orderSql.$limitSql);
    while ($row = $dataResult->fetchArray(SQLITE3_ASSOC)) {
        $obj = array($row['first_name'], $row['last_name'], $row['position'],$row['office'], $row['start_date'], $row['salary']);
        array_push($infos,$obj);
    }
}

/*
 * Output 包含的是必要的
 */
echo json_encode(array(
    "draw" => intval($draw),
    "recordsTotal" => intval($recordsTotal),
    "recordsFiltered" => intval($recordsFiltered),
    "data" => $infos
),JSON_UNESCAPED_UNICODE);


function fatal($msg)
{
    echo json_encode(array(
        "error" => $msg
    ));
    exit(0);
}

%5B=>[
%5D=>]
http://dt.thxopen.com/example/resources/server_processing_customCUrl.php?
draw=1&
columns[0][data]=0&columns[0][name]=&columns[0][searchable]=true&columns[0][orderable]=true&columns[0][search][value]=&columns[0][search][regex]=false&
columns[1][data]=1&columns[1][name]=&columns[1][searchable]=true&columns[1][orderable]=true&columns[1][search][value]=&columns[1][search][regex]=false&
columns[2][data]=2&columns[2][name]=&columns[2][searchable]=true&columns[2][orderable]=true&columns[2][search][value]=&columns[2][search][regex]=false&
columns[3][data]=3&columns[3][name]=&columns[3][searchable]=true&columns[3][orderable]=true&columns[3][search][value]=&columns[3][search][regex]=false&
columns[4][data]=4&columns[4][name]=&columns[4][searchable]=true&columns[4][orderable]=true&columns[4][search][value]=&columns[4][search][regex]=false&
columns[5][data]=5&columns[5][name]=&columns[5][searchable]=true&columns[5][orderable]=true&columns[5][search][value]=&columns[5][search][regex]=false&
order[0][column]=0&
order[0][dir]=asc&
start=0&
length=10&
search[value]=&
search[regex]=false&
_=1418644693360