如何將正負記錄從計算所有餘額總和的查詢中分離出來......？

Question

select account 
    , SUM(balance) as bal 
from Main_report 
Group BY account 

如何從上述查詢中分離正面和負面記錄？ 我想結合這個查詢與下面列出的情況。

select (case when bal < 0 then bal else 0 end) as debits, 
(case when bal > 0 then bal else 0 end) as credits from Main_report 
Group BY account 

Answer 1

只需使用你的兩個案例，總結這些結果：

SELECT account 
    , SUM(CASE WHEN balance < 0 THEN balance ELSE 0 END) as debits 
    , SUM(CASE WHEN balance > 0 THEN balance ELSE 0 END) as credits 
FROM Main_report 
GROUP BY account