Sample Yii

Style jQuery-nya (Letakin di view yg mau dipake) :
===================================================
$(document).ready(function() {
    $("#id_element_harga_barang").attr('disabled', true); //Disable harga barang biar ga bisa diubah
    $("#id_element_kode_barangnya").change(function(){
    var kdbrg = $(this).val();
    $("#id_element_harga_barangnya").val(''); //Kosongin isi field harga
        $.ajax({
            type: 'POST',
            data: {
                    id: kdbrg ,
                    YII_CSRF_TOKEN: jQuery('input[name="YII_CSRF_TOKEN"]').val() //Baris ini dipake kalo aktifin CSRF. Kalo ga aktifin, hapus aja
            },
            url: '<?php echo $this->createAbsoluteUrl("nama_controller/ambilharga"); ?>',
            dataType: 'json',
            cache: false,
            success: function(result) {
                    $("#id_element_harga_barangnya").val(result[0].nama_field_harganya);
            },
            error: function(){
                    alert('Maaf, Pengambilan data error.');
            }
        });
    });
});


Controllernya :
==================
public function actionAmbilharga()
{
    if(Yii::app()->request->isAjaxRequest)
    {
        $id = $_POST['id'];
        $sql = "SELECT harga FROM nama_tabel WHERE kode_barang='$id'";
        $connection=Yii::app()->db;
        $command=$connection->createCommand($sql);
        $dataReader=$command->queryAll();
        echo CJSON::encode($dataReader);
    }
}