Oracle SubQuery（显示子查询列）

Question

我似乎无法通过搜索找到如何从下面的子查询中返回某些列。 特别是B.TAP_STAT_HSL / C.TAP_STAT_HSL。 我不确定我是否应该加入，但是任何帮助将不胜感激。

   SELECT 

   A.HSE_KEY_HSE AS HOUSEKEY,
   A.DROP_STAT_HSE AS DROPSTATUS
   A.TAP_STAT_HSL AS ITAPSTAT

   FROM OPS$SEA.HSE_BASE,OPS$SEA.HSL_LOB,OPS$SEA.OOR_ORDER_OPEN A

   WHERE A.HSE_KEY_HSE = A.HSE_KEY_HSL 
   AND A.HSE_KEY_HSL = A.HSE_KEY_OOR
   AND A.DROP_STAT_HSE = '1'
   AND A.LOB_IND_HSL = 'I'
   AND A.TAP_STAT_HSL IN ('0','2')
   AND A.ORD_STAT_OOR <> 'O'
   AND EXISTS (SELECT 1

   FROM OPS$SEA.HSE_BASE B,OPS$SEA.HSL_LOB B, OPS$SEA.OOR_ORDER_OPEN B

   WHERE A.HSE_KEY_HSE = B.HSE_KEY_HSE
   AND B.HSE_KEY_HSE = B.HSE_KEY_HSL
   AND B.HSE_KEY_HSL = B.HSE_KEY_OOR 
   AND B.DROP_STAT_HSE = '1'
   AND B.LOB_IND_HSL = 'C'
   AND B.TAP_STAT_HSL IN ('0','2')
   AND B.ORD_STAT_OOR <> 'O')
   AND EXISTS (

   SELECT 1

   FROM OPS$SEA.HSE_BASE C,OPS$SEA.HSL_LOB C, OPS$SEA.OOR_ORDER_OPEN C

   WHERE A.HSE_KEY_HSE = C.HSE_KEY_HSE
   AND C.HSE_KEY_HSE = C.HSE_KEY_HSL 
   AND C.HSE_KEY_HSL = C.HSE_KEY_OOR
   AND C.DROP_STAT_HSE = '1'
   AND C.LOB_IND_HSL = 'T'
   AND C.TAP_STAT_HSL IN ('0','2')
   AND C.ORD_STAT_OOR <> 'O')}

Answer 1

嗯...

我相信您的查询可以重新编写如下：

WITH Allowed_Rows (houseKey, dropStatus, ipApStat, indicator) 
                   as (SELECT a.HSE_KEY_HSE, a.DROP_STAT_HSE, 
                              b.TAP_STAT_HSL, b.LOB_IND_HSL
                       FROM OPS$SEA.HSE_BASE as a
                       JOIN OPS$SEA.HSL_LOB as b
                       ON b.HSE_KEY_HSL = a.HSE_KEY_HSE
                       AND b.LOB_IND_HSL IN ('I', 'C', 'T')
                       AND b.TAB_STAT_HSL IN ('0', '2')
                       JOIN OPS$SEA.OOR_Order_Open as c
                       ON c.HSE_KEY_OOR = a.HSE_KEY_HSE
                       AND c.ORD_STAT_OOR <> '0'
                       WHERE a.DROP_STAT_HSE = '1')
SELECT houseKey, dropStatus, ipApStat
FROM Allowed_Rows as a
WHERE a.indicator = 'I'
AND EXISTS (SELECT '1' 
            FROM Allowed_Rows as b
            WHERE b.houseKey = a.houseKey
            AND b.indicator = 'C')
AND EXISTS (SELECT '1'
            FROM Allowed_Rows as b
            WHERE b.houseKey = a.houseKey
            AND b.indicator = 'T')

您没有适当地限定某些表，并为多个表使用了相同的别名（我很惊讶没有产生语法错误），因此我不得不对事物的实际位置做出最好的猜测。 取决于其他（未列出）的要求和约束，还有其他几种可能的变化。

以及为什么以及如何需要返回TAP_STAT_HSL的“其他”值？ 您是否需要所有可能的组合？ B或C 而不是 A的行的值？ 什么？