如何比较一列中的值并将其作为条件语句？

Question

所以我有这张桌子：

DATE	NAME	REFERENCE	ITEM_NUMBER	TOTAL
03/06/2021	XYC	SAFGASZXFEW	Z1-100-0006	102
03/06/2021	XYC	SAFGASZXFEW	Z1-100-0002	200
03/06/2021	XYC	SAFGASZXFEW	A2-50-0003	329
03/06/2021	XYC	SAFGASZXFEW	A2-50-0007	431
03/07/2021	ZBA	DSHDRFBVDRF	RV-100-0001	653
03/07/2021	ZBA	DSHDRFBVDRF	RV-100-0004	222
03/07/2021	ZBA	DSHDRFBVDRF	A2-50-0002	643

我尝试用这个查询转置 item_number 表：

SUM(CASE WHEN ITEM_NUMBER like '%-100-%' THEN CAST(TOTAL AS INT)END) 100_1ST,

SUM(CASE WHEN ITEM_NUMBER like '%-100-%' AND (**ITEM_NUMBER<>ITEM_NUMBER**) THEN CAST(TOTAL AS INT)END) 100_2ND,

SUM(CASE WHEN ITEM_NUMBER like '%-50-%' THEN CAST(TOTAL AS INT)END) 50_1ST,

SUM(CASE WHEN ITEM_NUMBER like '%-50-%' AND (**ITEM_NUMBER<>ITEM_NUMBER**) THEN CAST(TOTAL AS INT)END) 50_2ND,

我得到了结果：

DATE	NAME	REFERENCE	100_1ST	100_2ND	50_1ST	50_2ND
03/06/2021	XYC	SAFGASZXFEW	202	NULL	760	NULL
03/07/2021	ZBA	DSHDRFBVDRF	875	NULL	643	NULL

而我预期的结果是这样的：

DATE	NAME	REFERENCE	100_1ST	100_2ND	50_1ST	50_2ND
03/06/2021	XYC	SAFGASZXFEW	100	200	329	431
03/07/2021	ZBA	DSHDRFBVDRF	653	222	643	NULL

我知道我对 100_2ND 和 50_2ND 的条件语句的查询是错误的，我仍然不知道如何比较一列中的两个值，例如（Z1-100-0006 & Z1-100-0002) 它们具有相同的 '%-100-%' 属性，但仅通过它们的最后一位数字来区分，因此我可以将 TOTAL 值放入不同的列中。谁能帮帮我？

Answer 1

我想你想要row_number()。目前尚不清楚您是如何确定第一项和第二项的，但如下所示：

SELECT date,
       SUM(CASE WHEN ITEM_NUMBER LIKE '%-100-%' AND seqnum = 1 THEN TOTAL END) as 100_1ST,
       SUM(CASE WHEN ITEM_NUMBER LIKE '%-100-%' AND seqnum = 2 THEN TOTAL END) as 100_2ND,
       SUM(CASE WHEN ITEM_NUMBER LIKE '%-50-%' AND seqnum = 1 THEN TOTAL END) as 50_1ST,
       SUM(CASE WHEN ITEM_NUMBER LIKE '%-50-%' AND seqnum = 2 THEN TOTAL END) as 50_2ND
FROM (SELECT t.*,
             ROW_NUMBER() OVER (PARTITION BY SUBSTRING_INDEX(SUBSTRING_INDEX(item_number, '-', 2), '-', -1)
                                ORDER BY item_number
                               ) as seqnum
      FROM t
     ) t
GROUP BY date;