这是我的表结构。
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main_section | date_of_pay | currency | amount
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Tender 20-02-2016 INR 2000
Tender 20-02-2016 INR 1500
Tender 20-02-2016 INR 1850
PBG 20-02-2016 INR 1850
SD 20-02-2016 INR 1850
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我试图做一个CASE声明，如果'main_section = Tender'它应该返回投标金额，currency和date_of_pay。如果它的PBG它应该返回PBG金额，货币和date_of_pay。同时为SD。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。它工作正常，但没有显示date_of_pay，它显示为空（NULL）。
SELECT
SUM(CASE WHEN main_section = 'Tender' THEN com_payments.amount END) AS tendamount,
SUM(CASE WHEN main_section = 'SD' THEN com_payments.amount END) AS banksdamount,
SUM(CASE WHEN main_section = 'PBG' THEN com_payments.amount END) AS bankpbgamount,
MAX(CASE WHEN main_section = 'Tender Fee' THEN com_payments.amt_curr END) AS tendcurrency,
MAX(CASE WHEN main_section = 'Bank Guarantee SD' THEN com_payments.amt_curr END) AS banksdcurrency,
MAX(CASE WHEN main_section = 'Bank Guarantee PBG' THEN com_payments.amt_curr END) AS bankpbgcurrency,
CASE WHEN main_section = 'Tender Fee' THEN com_payments.date_of_pay END AS tendbankdop,
CASE WHEN main_section = 'Bank Guarantee SD' THEN com_payments.date_of_pay END AS banksdbankdop,
CASE WHEN main_section = 'Bank Guarantee PBG' THEN com_payments.date_of_pay END AS bankpbgbankdop
FROM TABLE
可能是我犯了一个错误。不确定。有人帮我吗？