cmd.CommandText = "select DISTINCT 出库单号,出库日期,气瓶容积,满瓶数量,气瓶单价,其他费用,气体名称 from {出库明细表} as a where exists (select 出库单号 from {租金计算明细表} as b where a.出库单号 = b.原出库单号 and IIF(a.满瓶数量 is null,0,a.满瓶数量)>IIF(b.空瓶数量 is null,0,b.空瓶数量) and a.气体名称=b.气体名称 and a.气瓶容积=b.气瓶容积)"