以2位小數顯示SQL中的計算結果

Question

我寫了一個簡單的查詢來找出兩列的百分比，但我希望結果在只有兩位小數的列中。這是我寫的，但我遇到了錯誤，而且我似乎無法修復它。

SELECT 
    Small_Bags,
    Total_Bags,
    (Small_Bags / Total_Bags) * 100 AS Small_Bags_Percent
    (Select CAST (Small_Bags_Percent AS DECIMAL (10,2)))
FROM Table_Bags
WHERE Total_Bags <>0

Answer 1

您不能在同一查詢中使用列別名。你可以做到這一點。

select Small_Bags
    , Total_Bags
    , (Small_Bags / Total_Bags) * 100 AS Small_Bags_Percent
    , cast(((Small_Bags / Total_Bags) * 100) as decimal(10,2))
from Table_Bags
where Total_Bags > 0

或使用子查詢

select t1.Small_Bags, t1.Total_Bags, t1.Small_Bags_Percent
    , cast(t1.Small_Bags_Percent as decimal(10,2))
from 
    (select Small_Bags
        , Total_Bags
        , (Small_Bags / Total_Bags) * 100 AS Small_Bags_Percent
        , cast(((Small_Bags / Total_Bags) * 100) as decimal(10,2))
    from Table_Bags
    where Total_Bags > 0) t1