COUNT（DISTINCT（以（'A'，'B'

Question

大家好，想知道是否有人可以提供以下幫助：

SELECT
  HOST_ORDER_NO,
  EARLIEST_PICK_DATE,
  PRODUCT_NO,
  PRODUCT_NUM_PARTS,
  PRODUCT_WHS_LOCATION,
  COUNT(DISTINCT(CASE 
   WHEN LEFT(PRODUCT_WHS_LOCATION,1) IN ('A','B','C','K','M','N') THEN 'BULK'
   WHEN LEFT(PRODUCT_WHS_LOCATION,1) IN ('D','E','F') THEN 'TEN'
   WHEN LEFT(PRODUCT_WHS_LOCATION,1) IN ('G','H','I','J','L') THEN 'TENSMALL'
   ELSE 'SIP' END) AS 'ZONE',
  MAX(COLLATION_INDICATOR),
  COLLATION_GROUP_ID,
  CASE WHEN COUNT(HOST_ORDER_NO)=1 THEN 'SingleOrder' ELSE 'MultiItem' END AS 'OrderType',
  COUNT(*) AS 'ItemsInOrder',
  YEARWEEK
FROM wk19
  WHERE YearWeek = '201717'
  GROUP BY HOST_ORDER_NO
  HAVING OrderType = 'MultiItem'
  ORDER BY HOST_ORDER_NO, COLLATION_GROUP_ID, MAX(COLLATION_INDICATOR);

我的錯誤是在案例陳述中，我希望能夠查看訂單來自倉庫的不同區域。 該語句的其余部分工作正常，但是如果我需要簡化一下，我可以做。

Answer 1

您的case 表達式僅缺少括號。 之后無需括號distinct ，所以：

COUNT(DISTINCT CASE WHEN LEFT(PRODUCT_WHS_LOCATION,1) IN ('A','B','C','K','M','N') THEN 'BULK'
                    WHEN LEFT(PRODUCT_WHS_LOCATION,1) IN ('D','E','F') THEN 'TEN'
                    WHEN LEFT(PRODUCT_WHS_LOCATION,1) IN ('G','H','I','J','L') THEN 'TENSMALL'
                     ELSE 'SIP'
               END) AS ZONE,

忠告：僅對字符串和日期使用單引號。 不要將它們用作列別名。