如何在datatable [row child]中连接多个表

Question

我正在使用数据表服务器端行子功能row child但我需要使用join从两个表中获取数据。我怎样才能获得所需的结果。这是我的ajax文件：

<?php

/*
 * DataTables example server-side processing script.
 *
 * Please note that this script is intentionally extremely simply to show how
 * server-side processing can be implemented, and probably shouldn't be used as
 * the basis for a large complex system. It is suitable for simple use cases as
 * for learning.
 *
 * See http://datatables.net/usage/server-side for full details on the server-
 * side processing requirements of DataTables.
 *
 * @license MIT - http://datatables.net/license_mit
 */

/* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *
 * Easy set variables
 */

// DB table to use
$table = 'datatables_demo';

// Table's primary key
$primaryKey = 'id';

// Array of database columns which should be read and sent back to DataTables.
// The `db` parameter represents the column name in the database, while the `dt`
// parameter represents the DataTables column identifier - in this case object
// parameter names
$columns = array(
    array(
        'db' => 'id',
        'dt' => 'DT_RowId',
        'formatter' => function( $d, $row ) {
            // Technically a DOM id cannot start with an integer, so we prefix
            // a string. This can also be useful if you have multiple tables
            // to ensure that the id is unique with a different prefix
            return 'row_'.$d;
        }
    ),
    array( 'db' => 'name', 'dt' => 'name' ),
    array( 'db' => 'position',   'dt' => 'position' ),
    array( 'db' => 'office',     'dt' => 'office' ),
    array( 'db' => 'salary',     'dt' => 'salary' ),
    array( 'db' => 'extn',     'dt' => 'extn' ),

    array(
        'db'        => 'salary',
        'dt'        => 'salary',
        'formatter' => function( $d, $row ) {
            return '$'.number_format($d);
        }
    )
);

$sql_details = array(
    'user' => 'root',
    'pass' => '',
    'db'   => 'phwdata',
    'host' => 'localhost'
);


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

require( 'ssp.class.php' );

echo json_encode(
    SSP::simple( $_GET, $sql_details, $table, $primaryKey, $columns )
);

这是我的javascript：

function format ( d ) {
    // `d` is the original data object for the row
    return '<div class="slider">'+
        '<table cellpadding="5" cellspacing="0" border="0" style="padding-left:50px;">'+
            '<tr>'+
                '<td>Full name:</td>'+
                '<td>'+d.name+'</td>'+
            '</tr>'+
            '<tr>'+
                '<td>Extension number:</td>'+
                '<td>'+d.extn+'</td>'+
            '</tr>'+
            '<tr>'+
                '<td>Extra info:</td>'+
                '<td>And any further details here (images etc)...</td>'+
            '</tr>'+
        '</table>'+
    '</div>';
}

$(document).ready(function() {
    var table = $('#example').DataTable( {
        "ajax": 'ajax.php',
        "columns": [
            {
                "class":          'details-control',
                "orderable":      false,
                "data":           null,
                "defaultContent": ''
            },
            { "data": "names" },
            { "data": "position" },
            { "data": "office" },
            { "data": "salary" },
            { "data": "extn", "visible": false }

        ],
        "order": [[1, 'asc']]
    } );

    // Add event listener for opening and closing details
    $('#example tbody').on('click', 'td.details-control', function () {
        var tr = $(this).closest('tr');
        var row = table.row( tr );

        if ( row.child.isShown() ) {
            // This row is already open - close it
            $('div.slider', row.child()).slideUp( function () {
                row.child.hide();
                tr.removeClass('shown');
            } );
        }
        else {
            // Open this row
            row.child( format(row.data()), 'no-padding' ).show();
            tr.addClass('shown');

            $('div.slider', row.child()).slideDown();
        }
    } );
} );
</script>

所以我想内部加入一个表“契约”。这可能在数据表中。我谷歌它，但我没有找到任何我可以在我的代码中实现并获得所需的结果。任何帮助都会非常值得赞赏。