如何将下面的语句中的 *= 改为 left joinselect a.drug_id,a.quantity as neednum,sum(isnull(b.quantity,0)) as stocknum
from order_detail a,channel_stock b
where a.order_no='11' and machine_id in ('k','h') and a.drug_id *= b.drug_id
group by a.drug_id,a.quantity
from order_detail a,channel_stock b
where a.order_no='11' and machine_id in ('k','h') and a.drug_id *= b.drug_id
group by a.drug_id,a.quantity
from order_detail a
left join channel_stock b
on a.drug_id = b.drug_id
where a.order_no='11' and machine_id in ('k','h')
group by a.drug_id,a.quantity
我这查出来的结果不一样啊
×=:
30007 2 16
30015 2 0
left join:
30007 2 16
from order_detail a
left join channel_stock b
on a.drug_id = b.drug_id
and a.order_no='11' and machine_id in ('k','h')
group by a.drug_id,a.quantity