情况下，当结果不准确

Question

SELECT 
DATE_TRUNC('day', payment.paid_at) AS "DAILY", 
COUNT(CASE WHEN product.type = 'A' THEN 1 ELSE NULL END) AS "A count", 
SUM(CASE WHEN product.type = 'A' AND payment.price_currency_code='USD' THEN payment.price_amount*1080 ELSE payment.price_amount END) AS "A revenue", 
COUNT(CASE WHEN product.type = 'B' THEN 1 ELSE NULL END) AS "B count", 
SUM(CASE WHEN product.type = 'B' AND payment.price_currency_code='USD' THEN payment.price_amount*1080 ELSE payment.price_amount END) AS "B revenue" 

嗨，

当使用“CASE WHEN” 我已经写了如上的查询，但结果是不准确我有一个问题。实际上，每个类别的收入总和几乎相同，实际上它应该是不同的（但计数是正确的）。

如果你能指出我失踪或做错了，我将不胜感激！

谢谢:)

Answer 1

有没有在你的ELSE语句中的错误，因为它包括一切的时候，其实你可能是为了不同的条件：

SELECT 
DATE_TRUNC('day', payment.paid_at) AS "DAILY", 
COUNT(CASE WHEN product.type = 'A' THEN 1 END) AS "A count", 
SUM(CASE WHEN product.type = 'A' AND payment.price_currency_code='USD' THEN payment.price_amount*1080 WHEN product.type = 'A' THEN payment.price_amount END) AS "A revenue", 
COUNT(CASE WHEN product.type = 'B' THEN 1 END) AS "B count", 
SUM(CASE WHEN product.type = 'B' AND payment.price_currency_code='USD' THEN payment.price_amount*1080 WHEN product.type = 'B' THEN payment.price_amount END) AS "B revenue" 

此外，case语句ELSE NULL不是必需的，因为NULL是非匹配的默认结果。