带有SUM的CASE语句

Question

这是我的表结构。

===================================
main_section | currency | amount
===================================

Tender           INR        2000
Bank             USD        3000
Tender           INR        1500
Tender           INR        1850
===================================

我试图做一个CASE陈述，其中如果＆＃39; main_section =招标＆＃39;它应该返还投标金额，如果它的银行应该返还银行金额。如果有多个记录，那么它应该总和并返回金额（此处招标有多个记录）。谁能帮我这个。以下是我试过的案例陈述

CASE sum(com_payments.main_section 
         WHEN com_payments.main_section = 'Tender' 
         THEN main_tender = com_payments.amount
END AS maintender1)
CASE sum(com_payments.main_section 
         WHEN com_payments.main_section = 'Bank' 
         THEN main_bank = com_payments.amount
END AS mainbank1)

Answer 1

您必须执行条件聚合：

SELECT SUM(CASE WHEN main_section = 'Tender' THEN amount END) AS maintender1,
       SUM(CASE WHEN main_section = 'Bank' THEN amount END) AS mainbank1      
FROM mytable