public decimal GetAvgOrderAmount(string startDate, string endDate)
{
using (var db = new PermaisuriCMSEntities())
{
//注意，第一个输出参数的名称必须与Store Procedure里面的输出参数的名称一一对应！不区分大小写
var retVal = db.Ecom_AvgOrderAmount_SP(startDate, endDate);
return(retVal.First().AvgOrderAmount.ConvertToNotNull());
}
}