视图模型求助

视图模型这样不行吗？不能重复一个表里面的字段吗？
class CashViewModel extends ViewModel{ protected $viewFields = array( 'fi_cash_tran' => array('id','pay','income','money','time','user','remark','_type'=>'LEFT'), 'fi_cash' => array('bank'=>'ibank','name'=>'iname','_on'=>'fi_cash.id=fi_cash_tran.income'), 'fi_cash' => array('bank'=>'pbank','name'=>'pname','_on'=>'fi_cash.id=fi_cash_tran.pay'), ); }