與多個連接和條件的Mysql查詢

Question

我想連接四個表使用關節，在這裏我用左連接來連接表和我的條件是所有的商品，項目應該是相同的，所有的網站應該是same.same網站有多件商品，所以我想從每張桌子上得到商品的總數。我的查詢給出

select 
    a.goods 
    ,sum(a.no_of_units) as totala 
    , a.site 
    ,b.item 
    ,sum(b.quantity) as totalb 
    ,b.site 
    ,c.goods 
    ,c.site 
    ,sum(c.no_of_units) as totalc 
    ,d.site 
    ,d.goods 
    ,sum(d.quantity)b as totald 
from 
    inward_stock a 
left join 
    opening_balance b 
on 
    a.site=b.site 
and 
    a.goods=b.item 
left join 
    return_stock c 
on 
    b.site=c.site 
and 
    b.item=c.goods 
left join 
    stock_consumed d 
on 
    d.site=c.site 
and 
    d.goods=c.goods 

Answer 1

你能不能把你的條件，在關節處的像這樣的結尾：

select a.goods,sum(a.no_of_units) as totala, a.site,b.item,sum(b.quantity) as totalb,b.site,c.goods,c.site,sum(c.no_of_units) as totalc,d.site,d.goods,sum(d.quantity) as totald 
 
from inward_stock a left join 
 
    opening_balance b on (a.site=b.site) left join 
 
    return_stock c on (b.site=c.site) left join 
 
    stock_consumed d on (d.site=c.site) where (a.goods=b.item) and (b.item=c.goods) and (d.goods=c.goods)

我沒有測試過您的要求，但它似乎不是壞。