情況下，當結果不準確

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，

當使用「CASE WHEN」 我已經寫了如上的查詢，但結果是不準確我有一個問題。實際上，每個類別的收入總和幾乎相同，實際上它應該是不同的（但計數是正確的）。

如果你能指出我失蹤或做錯了，我將不勝感激！

謝謝:)

Answer 1

有沒有在你的ELSE語句中的錯誤，因爲它包括一切的時候，其實你可能是爲了不同的條件：

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語句ELSE NULL不是必需的，因爲NULL是非匹配的默認結果。