用戶定義的日期分區sql

Question

我有一張表，它提供了每天不同項目的單位銷售額。我想總結一些用戶定義（有效任意，無法直接從數據中指定）期間的銷售額。

我試圖通過創建一個字段，指定是否在期限內的日期，然後我可以通過這個分組。但是，我的代碼給我錯誤「ORA-00923：FROM關鍵字找不到預期的地方」。

我的代碼：

select 
SUM(UNIT_SALES), 
PERIOD = 
    CASE 
      WHEN DAY_DATE >= TO_DATE('04/07/2013', 'DD/MM/YYYY') AND DAY_DATE <= TO_DATE('26/09/2013', 'DD/MM/YYYY') THEN 'Start of Period of pre_activity' 
      WHEN DAY_DATE >= TO_DATE('27/09/2013', 'DD/MM/YYYY') AND DAY_DATE <= TO_DATE('01/04/2014', 'DD/MM/YYYY') THEN 'Start of Period of pre_activity' 
      WHEN DAY_DATE >= TO_DATE('14/05/2014', 'DD/MM/YYYY') AND DAY_DATE <= TO_DATE('21/09/2014', 'DD/MM/YYYY') THEN 'Start of Period of pre_activity' 
      ELSE 'NO PERIOD ASSIGNED' 
    END 
FROM MY_SALES_DAILY 
GROUP BY PERIOD 
ORDER BY PERIOD 

我怎樣才能做到這一點和用戶定義的時間段？

Answer 1

您的語法不正確。 PERIOD =不正確。請參閱下面的更正的SQL。

select 
SUM(UNIT_SALES), 
    CASE 
      WHEN DAY_DATE >= TO_DATE('04/07/2013', 'DD/MM/YYYY') AND DAY_DATE <= TO_DATE('26/09/2013', 'DD/MM/YYYY') THEN 'Start of Period of pre_activity' 
      WHEN DAY_DATE >= TO_DATE('27/09/2013', 'DD/MM/YYYY') AND DAY_DATE <= TO_DATE('01/04/2014', 'DD/MM/YYYY') THEN 'Start of Period of pre_activity' 
      WHEN DAY_DATE >= TO_DATE('14/05/2014', 'DD/MM/YYYY') AND DAY_DATE <= TO_DATE('21/09/2014', 'DD/MM/YYYY') THEN 'Start of Period of pre_activity' 
      ELSE 'NO PERIOD ASSIGNED' 
    END AS PERIOD 
FROM DW_MASTER_SALES_DAILY 
GROUP BY  CASE 
      WHEN DAY_DATE >= TO_DATE('04/07/2013', 'DD/MM/YYYY') AND DAY_DATE <= TO_DATE('26/09/2013', 'DD/MM/YYYY') THEN 'Start of Period of pre_activity' 
      WHEN DAY_DATE >= TO_DATE('27/09/2013', 'DD/MM/YYYY') AND DAY_DATE <= TO_DATE('01/04/2014', 'DD/MM/YYYY') THEN 'Start of Period of pre_activity' 
      WHEN DAY_DATE >= TO_DATE('14/05/2014', 'DD/MM/YYYY') AND DAY_DATE <= TO_DATE('21/09/2014', 'DD/MM/YYYY') THEN 'Start of Period of pre_activity' 
      ELSE 'NO PERIOD ASSIGNED' 
      END 
ORDER BY PERIOD