Ajax连接select和total记录查询

I've a php page where there is a ajax concatenate select and a div with the total number of records in the table tb1

HTML

<p>
<select name="model" id="model">
        <?php echo $myclass->selModel(); ?>
</select>
</p>
<br />
<p>
<select name="year" id="year">
    <option value="">&nbsp;</option>
</select>
</p>
<p>
<div id="total"><?php echo $myclass->recordNum();?></div>
</p>

JS

// VARS 
var wait = '<option>Waiting</option>';
var select = '<option value="">Select</option>';

// CAT_1 //
$("select#model").change(function(){

    var model = $("select#model option:selected").prop("value");
            $("select#year").html(wait);


    $.post("ajax-php/select-concat.php", {model:model}, function(data){

        switch (data) {

            case select:
                $("select#year").html("");
            return false;

            default:
                $("select#year").prop("disabled", false);
                $("select#year").html(data);
            return false;
        }
    });
});

PHP - select-concat.php

if(isset($_POST['model']))
{
echo $myclass->selYear();
die;
}

MY PHP CLASS

public function selYear() {


    $result = $this->db->mysqli->query
    ("SELECT year FROM tb1 WHERE model='$_POST[model]");        

    $year = '<option value="">Select</option>';

        while($row = $result->fetch_assoc()) {

            $year .= '<option value="' . $row['year'] . '"';
            $year .= '>' . $row['year'] . '</option>';
        }

    return $year;
}

private function recordNum(){

    $result = $this->db->mysqli->query
    ("SELECT * FROM tb1 WHERE something ");

        $numrec = $result->num_rows;

    return $numrec;
}

My goal is to update the number of records with ajax every time I run a concatenate select. How could I do that? Thanks

You should use json_encode() on select-concat.php to return two results.

if(isset($_POST['model']))
{
    $years = $myclass->selYear();
    $total = $myclass->recordNum();

    $arr = array('years' => $years, 'total' => $total);

    echo json_encode($arr);

    die;
}

You must add POST model value to recordNum() function (or pass it with an argument).

Then...

$("select#model").change(function(){

    var model = $("select#model option:selected").prop("value");
            $("select#year").html(wait);


    $.post("ajax-php/select-concat.php", {model:model}, function(data){
        var json_data = $.parseJSON(data);

        switch (data) {

            case select:
                $("select#year").html("");
                $("#total").html(0);
            return false;

            default:
                $("select#year").prop("disabled", false);
                $("select#year").html(json_data.years);
                $("#total").html(json_data.total);
            return false;
        }
    });
});