如果条件在右表中满足而不使用子查询oracle，如何排除左表中的所有行

Question

我有两个表，BATCH_MESSAGES，BATCH_INSTRUCTIONS，如果其中任何指令的状态为暂停/拒绝，我想排除所有批次。

这里左边是 BATCH_MESSAGES，右边是 BATCH_INSTRUCTIONS。

这是 BATCH_MESSAGES 的 DDL

这是针对：BATCH_INSTRUCTIONS

仅应输出“CDC-SCBP-862411139626”，因为它是唯一一个所有指令状态为 NOT IN 暂停/拒绝。

我的查询产生相同的结果但它使用子查询复杂且效率低下。有没有更好的方法？

SELECT DISTINCT BM.ID,
         BM.BATCH_MSG_TYPE,
         BM.PARENT_BATCH_ID
FROM iris_activity.BATCH_MESSAGES BM 
WHERE BM.INSTRUCTIONS_COUNT = BM.PROCESSED_INSTRUCTIONS
AND BM.STAGE NOT IN ('COMPLETED')
AND BM.BATCH_MSG_TYPE NOT LIKE 'pacs.004%'
AND BM.RECEIVING_MODE = 'Stream' 
AND BM.ID NOT IN (SELECT DISTINCT BATCH_ID 
                  FROM iris_activity.BATCH_MESSAGES bm 
                  INNER JOIN Iris_activity.BATCH_INSTRUCTIONS bi  
                         on (bm.id = bi.BATCH_ID 
                            and bm.BATCH_MSG_TYPE = bi.BATCH_TYPE)
                   WHERE STATUS IN ('Suspended','Rejected') 
                   GROUP BY BATCH_ID, STATUS)
AND BM.RETRIES              <=5 ;

这样可以更高效、更简单吗？

Answer 1

您可以在查询中使用分析函数COUNT，只需进行少量重写，如下所示：

Select DISTINCT BM.ID,
       BM.BATCH_MSG_TYPE,
       BM.PARENT_BATCH_ID
  From
    (SELECT BM.*,
            COUNT(CASE WHEN BI.STATUS IN ('Suspended','Rejected') THEN 1 END) 
                  Over(partition by BM.ID) AS CNT -- analytical function
       FROM iris_activity.BATCH_MESSAGES BM 
       LEFT JOIN Iris_activity.BATCH_INSTRUCTIONS bi
         ON bm.id = bi.BATCH_ID and bm.BATCH_MSG_TYPE = bi.BATCH_TYPE
      WHERE BM.INSTRUCTIONS_COUNT = BM.PROCESSED_INSTRUCTIONS
        AND BM.STAGE NOT IN ('COMPLETED')
        AND BM.BATCH_MSG_TYPE NOT LIKE 'pacs.004%'
        AND BM.RECEIVING_MODE = 'Stream' 
        AND BM.RETRIES <= 5            
    ) BM
 WHERE BM.CNT = 0 -- this condition

Answer 2

您可以将 NOT IN 子查询转换为左连接的内联视图，并添加一个谓词以确保内联视图中的值为 NULL。

SELECT DISTINCT BM.ID,
         BM.BATCH_MSG_TYPE,
         BM.PARENT_BATCH_ID
FROM iris_activity.BATCH_MESSAGES BM 
LEFT JOIN
(
    SELECT DISTINCT BATCH_ID 
    FROM iris_activity.BATCH_MESSAGES bm 
    INNER JOIN Iris_activity.BATCH_INSTRUCTIONS bi  
            on (bm.id = bi.BATCH_ID 
           and bm.BATCH_MSG_TYPE = bi.BATCH_TYPE)
    WHERE STATUS IN ('Suspended','Rejected') 
    GROUP BY BATCH_ID, STATUS
) suspended_or_rejected
  on  BM.BM_ID = suspended_or_rejected_batches.BATCH_ID
WHERE BM.INSTRUCTIONS_COUNT = BM.PROCESSED_INSTRUCTIONS
AND BM.STAGE NOT IN ('COMPLETED')
AND BM.BATCH_MSG_TYPE NOT LIKE 'pacs.004%'
AND BM.RECEIVING_MODE = 'Stream' 
AND BM.RETRIES              <=5
--New predicate:
AND suspended_or_rejected.BATCH_ID IS NULL;

虽然此更改实际上比您的原始示例更复杂，但当您连接两个表中的大部分行时，这种方法通常会明显更快。 LEFT JOIN 更有可能使用哈希连接，这可能比嵌套循环和索引查找快得多。

但您还应该检查原始查询的执行计划。子查询不一定会使查询效率低下，因为 Oracle 通常能够重写查询并将子查询合并到主查询中。

Answer 3

如果Not in，您可以使用not exists 代替

SELECT DISTINCT BM.ID,
         BM.BATCH_MSG_TYPE,
         BM.PARENT_BATCH_ID
FROM iris_activity.BATCH_MESSAGES BM 
WHERE BM.INSTRUCTIONS_COUNT = BM.PROCESSED_INSTRUCTIONS
AND BM.STAGE NOT IN ('COMPLETED')
AND BM.BATCH_MSG_TYPE NOT LIKE 'pacs.004%'
AND BM.RECEIVING_MODE = 'Stream' 
AND NOT EXISTS (SELECT 1
                  FROM Iris_activity.BATCH_INSTRUCTIONS bi  
                         WHERE  bm.id = bi.BATCH_ID 
                            and bm.BATCH_MSG_TYPE = bi.BATCH_TYPE
                            and STATUS IN ('Suspended','Rejected') 
                            )
AND BM.RETRIES              <=5 ;