select a.BM_NAME,a.JT_NAME,c.WP_ID,b.MING_CHENG,b.DAN_WEI,b.PRICE,
c.NUM,c.NUM*bPRICE AS ZHONGJIA,CS
from a, b,
(select WP_ID ,sum(NUM) as NUM,count(WP_ID) AS CS
from b group by WP_ID) c
where a.LH_ID=b.LH_ID
and LH_DATE between 20071010104300 and 20071011170000
這條語句是正確的,還可以提高效率
在統(tǒng)計a表可以對應(yīng)多個b表,所以查詢出來可能有多條但是為了方便用戶查看,必須把他合并成一條,統(tǒng)計出該數(shù)量信息
select a.BM_NAME,a.JT_NAME,b.WP_ID,b.MING_CHENG,b.DAN_WEI,b.PRICE,
b.NUM*bPRICE AS ZHONGJIA,sum(NUM) as NUM,count(WP_ID) AS CS from a, b
這就會出錯