SQL减法

[skysmmg]

select distinct a.fGoods_name AS 物品名, b.fnum - c.fOrder_amount AS 库存 from t_goods a,t_stockin_detail b,t_saleout_detail c
where a.fGoods_id=b.fGoods_id and b.fGoods_id=c.fGoods_id and a.fGoods_id=c.fGoods_id order by fGoods_name
这样查出来的语句中fGoods_name存在没合并情况,求助怎么解决
例如
{DM版}L6 2
{DM版}L6 1
{DM版}L6 -2
{DM版}L6 3
01 6
01 -1
01 1
01 3

怎么让他查处的如下
{DM版}L6 4
01 9

[子陌红尘]

sum()+group by

[csdyyr]

select  a.fGoods_name AS 物品名, sum(b.fnum - c.fOrder_amount) AS 库存
 from t_goods a,t_stockin_detail b,t_saleout_detail c
where a.fGoods_id=b.fGoods_id and b.fGoods_id=c.fGoods_id and a.fGoods_id=c.fGoods_id 
group by fGoods_name

[Liyingyue_FFS]

select  a.fGoods_name AS 物品名, sum(b.fnum - c.fOrder_amount) AS 库存 from t_goods a,t_stockin_detail b,t_saleout_detail c 
where a.fGoods_id=b.fGoods_id and b.fGoods_id=c.fGoods_id and a.fGoods_id=c.fGoods_id order by fGoods_name 
group by a.fGoods_name 

用这个试一下

[dlpseeyou]

select a.fGoods_name AS 物品名,sum( b.fnum - c.fOrder_amount) AS 库存 from t_goods a,t_stockin_detail b,t_saleout_detail c
where a.fGoods_id=b.fGoods_id and b.fGoods_id=c.fGoods_id and a.fGoods_id=c.fGoods_id
group by a.fGoods_name order by fGoods_name

[skysmmg]

谢谢!!!你直接点出了我的错误!

[jimoshatan]

SELECT S_NAME,SUM(QTY)QTY
FROM A
GROUP BY S_NAME