模型类：
<?php
class SupplierModel extends RelationModel{
protected $_auto = array(

array('gys_yinhang','gys',3,'callback'),
array('gys_lianxiren','lianxiren',3,'callback'),

);
function gys(){

$kaihuhang=$_POST['kaihuhang'];
$zhanghu=$_POST['zhanghu'];
$zhanghao=$_POST['zhanghao'];
$count=count($kaihuhang);
//var_dump($count);
$data=array();
for($i=0;$i<$count;$i++){
$data[$i]['kaihuhang']=$kaihuhang[$i];
$data[$i]['zhanghu']=$zhanghu[$i];
$data[$i]['zhanghao']=$zhanghao[$i];
}
foreach ($data as $k=>$v){
if(!empty($v)){
$res[$k][$key] = $v;
}else{
unset($res[$k]);
}
}
// var_dump($gys);die;
return $data;

}
function lianxiren(){

$lianxiren=$_POST['lianxiren'];
$lianxirenzhiwei=$_POST['lianxirenzhiwei'];
$lianxirendianhua=$_POST['lianxirendianhua'];
$qq=$_POST['qq'];
$email=$_POST['email'];
$count=count($lianxiren);
//var_dump($count);die;
$data=array();
for($i=0;$i<$count;$i++){
$data[$i]['lianxiren']=$lianxiren[$i];
$data[$i]['lianxirenzhiwei']=$lianxirenzhiwei[$i];
$data[$i]['lianxirendianhua']=$lianxirendianhua[$i];
$data[$i]['qq']=$qq[$i];
$data[$i]['email']=$email[$i];
}
foreach ($data as $k=>$v){
if(!empty($v)){
$res[$k][$key] = $v;
}else{
unset($res[$k]);
}
}
// var_dump($gys);die;
return $data;

}


protected $_link = array(
'yinhang'=>array(
'mapping_type' => HAS_MANY,
'class_name' =>'yinhang',
'foreign_key' =>'gys_id',
// 'mapping_order' =>'shijian desc',
//'mapping_limit' =>'1',
//'mapping_fields'=>'gys_id',
'mapping_name'=>'yinhang',
'mapping_fields'=>'gys_yinghang',
),
'lianxiren'=>array(
'mapping_type' => HAS_MANY,
'class_name' =>'lianxiren',
'foreign_key' =>'gys_id',
'mapping_name'=>'lianxiren',
'mapping_fields'=>'gys_lianxiren',
),
);



}
?>

ACTION：

<?php
// 本类由系统自动生成，仅供测试用途
class SupplierAction extends CommonAction {
public function index(){
//dump($_SESSION);
$this->display();
}

public function addnew(){
$m=D('Supplier');
$a=$m->create();
// dump($_POST);
$arr=$m->relation(true)->add();
// dump($arr);die;
if($arr){
$this->ajaxReturn($arr,"添加成功",1);
}else{
$this->ajaxReturn($arr,"添加失败",0);
}
}
}
?>


firebug 响应信息：
<pre>array(18) {
["gysmingcheng"] => string(1) "1"
["jinrutime"] => string(10) "2013-07-08"
["gsyjibie"] => string(0) ""
["pingjitime"] => string(10) "2013-07-16"
["tuichutime"] => string(10) "2013-07-17"
["gsydizhi"] => string(0) ""
["youbian"] => string(0) ""
["dianhua"] => string(1) "1"
["chuanzhen"] => string(0) ""
["kaihuhang"] => array(2) {
[0] => string(1) "1"
[1] => string(1) "4"
}
["zhanghu"] => array(2) {
[0] => string(1) "2"
[1] => string(1) "5"
}
["zhanghao"] => array(2) {
[0] => string(1) "3"
[1] => string(1) "6"
}
["lianxiren"] => array(1) {
[0] => string(1) "1"
}
["lianxirenzhiwei"] => array(1) {
[0] => string(0) ""
}
["lianxirendianhua"] => array(1) {
[0] => string(1) "2"
}
["qq"] => array(1) {
[0] => string(0) ""
}
["email"] => array(1) {
[0] => string(1) "3"
}
["beizhu"] => string(0) ""
}
</pre>{"data":false,"info":"\u6dfb\u52a0\u5931\u8d25","status":0}

最后的结果是保存失败。。调试了好久都不行。请问哪里出错了呢？？？