SQL：減去兩列

Question

select content_type_code_id 
    , ABS(price) AS price
    , SUM(case when price >= 0 THEN 1 ELSE 0 END) AS debits
    , SUM(case when price < 0 THEN 1 ELSE 0 END) AS credits
from dbo.transaction_unrated  
where transaction_date >= '2012/05/01'
      and transaction_date < '2012/06/01'
      and content_provider_code_id in (1)
group by content_type_code_id, ABS(price) 
ORDER BY ABS(price) ASC  

以上查詢產生以下輸出：

content_type_code_id    price   debits  credits
1                      0.00      317    0
1                      0.99      178    1
1                      1.99      786    1

但是我想要這樣的東西：

content_type_code_id    price   debits  credits NetCount
    1                      0.00      317    0       317 
    1                      0.99      178    1       177 
    1                      1.99      786    1       785

NetCount =（借方 - 貸方）

當我嘗試為其創建另一列時，我收到錯誤。

Answer 1

只需添加：

SUM(case when price >= 0 THEN 1 ELSE 0 END) - 
    SUM(case when price < 0 THEN 1 ELSE 0 END) AS NetCount

作為你的最后一句話，所以你最終得到這個：

select content_type_code_id 
    , ABS(price) AS price
    , SUM(case when price >= 0 THEN 1 ELSE 0 END) AS debits
    , SUM(case when price < 0 THEN 1 ELSE 0 END) AS credits
    , SUM(case when price >= 0 THEN 1 ELSE 0 END) - 
        SUM(case when price < 0 THEN 1 ELSE 0 END) AS NetCount
from dbo.transaction_unrated  
where transaction_date >= '2012/05/01'
      and transaction_date < '2012/06/01'
      and content_provider_code_id in (1)
group by content_type_code_id, ABS(price) 
ORDER BY ABS(price) ASC  

Lamak的派生表格版本：

您還可以使用派生表使代碼更清晰：

select content_type_code_id,
    price, debits, credits, (debits - credits) as NetCount
from (
    select content_type_code_id 
        , ABS(price) AS price
        , SUM(case when price >= 0 THEN 1 ELSE 0 END) AS debits
        , SUM(case when price < 0 THEN 1 ELSE 0 END) AS credits
    from dbo.transaction_unrated  
    where transaction_date >= '2012/05/01'
          and transaction_date < '2012/06/01'
          and content_provider_code_id in (1)
    group by content_type_code_id, ABS(price) 
) YourDerivedTable
ORDER BY price ASC  

Answer 2

WITH tbl AS 
(
select content_type_code_id 
    , ABS(price) AS price
    , SUM(case when price >= 0 THEN 1 ELSE 0 END) AS debits
    , SUM(case when price < 0 THEN 1 ELSE 0 END) AS credits
from dbo.transaction_unrated  
where transaction_date >= '2012/05/01'
      and transaction_date < '2012/06/01'
      and content_provider_code_id in (1)
group by content_type_code_id, ABS(price) 
ORDER BY ABS(price) ASC  
)

SELECT content_type_code_id, proce, debits, credits, (debits - credits) netcount from tbl

Answer 3

晚上好。 我有一個類似的任務，發現只是添加一個列並更新它是非常短的。

我認為這可以在您的代碼生成數據庫之后完成。 如果它不適合您的情況，我將不勝感激。

ALTER TABLE 這里的表名是 ADD NetCount 整數 ;

此處更新表名稱 SET NetCount = Debits-Credits ;

筆記：

• 第一行添加一個名為NetCount的整數類型的列
• 第二行更新它是借記和貸記之間的差異
• sql命令是大寫的，特定於您的信息是斜體

祝好運！