Question

我有这张桌子：

| id_product | tw_kod | ean  |nazwa     |stan  |cena_detaliczna |
|      1     | 9007   | 9008 | ARR 2016 | 2    |            2490|
|     2      | 9008   | 90085| ION 2018 | NULL |            1450|

和这个查询：

select
    tw.id as id_product,
    tw.kod as tw_kod,
    tw.kod as ean,
    tw.nazwa as nazwa,
    sm.stanHandl as stan,
    cn.cena as cena_detaliczna
from 
    [HM].[TW] as tw
join 
    [SSCommon].[STElements] as elem on tw.znacznik = elem.Shortcut
left join 
    [HM].[SM] as sm on tw.id = sm.idtw
left join 
    [HM].[CN] as cn on tw.id = cn.idpm
where
    elem.Shortcut = '66'
    and elem.ElementKindId = '54'
    --and sm.magazyn = 2
    and cn.typceny = 1
order by 
    nazwa

有些产品在[HM]。[SM]表中，有些 - 不是。我使用LEFT JOIN [HM]。[SM]来显示[HM]。[TW]中的所有产品，但是当我使用WHERE子句（sm.magazyn = 2）时它没有显示我的产品，这就是为什么我评论它。我试图在WHERE中使用IF ELSE，但我没有正确的结果。感谢

Answer 1

只需在FROM部分添加谓词，如下所示：

select
    tw.id as id_product,
    tw.kod as tw_kod,
    tw.kod as ean,
    tw.nazwa as nazwa,
    sm.stanHandl as stan,
    cn.cena as cena_detaliczna
from [HM].[TW] as tw
join [SSCommon].[STElements] as elem on tw.znacznik = elem.Shortcut
left join [HM].[SM] as sm on tw.id = sm.idtw and sm.magazyn = 2
left join [HM].[CN] as cn on tw.id = cn.idpm and cn.typceny = 1
where
    elem.Shortcut = '66'
    and elem.ElementKindId = '54'
    order by nazwa

对NULL的同情导致空结果集

SQL Server：如何在WHERE子句中使用IF ELSE或其他东西

1 个答案: