select count(a.orderno) cnt,b.name from busiorder a left join busigoods b on (b.goodsid = a.goodsid) where a.goodsid in ("+pubGoodsId+") and a.type=0 and a.createtime between ? and ? group by b.name 这是select语句,按时间查询时,有时数据库中的数据为空值,如何让他显示为零?