关联字段

'product_id':fields.many2one('product.product',u'产品',domain=[('sale_ok', '=', True)],required=True,),
'pname': fields.related('product_id', 'pname',relation='product.product', type="char", string=u'品名/材质',readonly=True,),
'spec': fields.related('product_id', 'spec',relation='product.product', type="char", string=u'规格',readonly=True,),
'bm': fields.related('product_id', 'bm',relation='product.product', type="char", string=u'编码',readonly=True,),