调 SQL 服务器查询

Question

我的目标是清除块中的数据，并考虑在将 ID_COl 值放入 #temptable 后对其进行循环。

    DECLARE @PD datetime = DATEADD(day, -5, GETUTCDATE());
DELETE GP
  FROM dbo.Table_A N
 INNER JOIN dbo.Table_BL GP
    ON N.NOTIF_ID = GP.NOTIF_ID
 WHERE N.FCT_AUD_IND = 'Y'
   AND N.CRE_TMST    < @PD
   AND EXISTS (   SELECT 1 ID_COl
                    FROM dbo.Table_A AS N1
                   WHERE N1.NOTIF_APPL_ID        = N.NOTIF_APPL_ID
                     AND N1.SOR_NOTIF_APPL_GP_ID = N.SOR_NOTIF_APPL_GP_ID
                     AND N1.NOTIF_DLT_IND  = 'Y');

Answer 1

你强迫 SQL 服务器做一个嵌套循环来查找 Table_A 中的记录，但也许 SQL 服务器当你让他决定并加入时会找到更好的方法相反：

DECLARE @PD datetime = DATEADD(day, -5, GETUTCDATE());
WITH N1 AS (
  SELECT DISTINCT NOTIF_APPL_ID, SOR_NOTIF_APPL_GP_ID
  FROM dbo.Table_A
  WHERE NOTIF_DLT_IND  = 'Y'
)
DELETE GP
FROM dbo.Table_A N
  INNER JOIN N1 ON N.NOTIF_APPL_ID = N1.NOTIF_APPL_ID 
               AND N.SOR_NOTIF_APPL_GP_ID = N1.SOR_NOTIF_APPL_GP_ID
  INNER JOIN dbo.Table_BL GP ON N.NOTIF_ID = GP.NOTIF_ID
WHERE N.FCT_AUD_IND = 'Y'
   AND N.CRE_TMST < @PD

此外，定义索引可能会有帮助。

调 SQL 服务器查询

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