Oracle中的Qualify子句

Question

我正在从事Teradata到Oracle的迁移项目。我如何修改以下在Teradata中使用QUALIFY的查询。

//查询1

   SELECT S.ID  as Id,
          S.MP_CD as Code,
          S.GM_CD  as GmCode,
          S.GM_MSR_NBR as Mea_Year, 
          S.STTS_CD as YearCode,
          S.TRMNTN_DTM as TerminationDate 
     FROM PD.RVY S, LOAD_LOG TLL 
    WHERE S.UPDTD_LOAD = TLL.LOG_KEY AND TLL.BLSH_CD = 'Y' AND S.STTS_CD IN ( 'C', 'P' ) 
  QUALIFY ROW_NUMBER () OVER (PARTITION BY S.GM_CD ,S.MP_CD ,S.GM_MSR_NBR,S.STTS_CD 
                              ORDER BY S.SO_DTM DESC 
                              ) = 1;

//查询2

  SELECT SP.ID,
         SP.SO_DTM,
         SP.TAX_ID,
         SP.USER_ID,
         SP.FRST_NM,
         SP.LAST_NM,
         SP.PHONE_NBR,
         QSRP.TAX_ID,
         QSRP.ROW_ID,
         MAX(SP.SO_DTM) OVER (PARTITION BY SP.ID, SP.TAX_ID) MAX_SO_DTM       
    FROM VOPR_RMSY SP,VOPR_RMSY_SPNS QSRP
    WHERE  SP.ID =:URVYID AND QSRP.TAX_ID =:RPAXID 
          AND SP.ID = QSRP.ID AND SP.TAX_ID = QSRP.TAX_ID AND SP.SO_DTM = QSRP.SO_DTM 
    QUALIFY (SP.SO_DTM=MAX_SO_DTM AND QSRP.SO_DTM = MAX_SO_DTM) 
    GROUP BY SP.ID,SP.SO_DTM,SP.TAX_ID,SP.USER_ID,SP.FRST_NM,SP.LAST_NM,SP.PHONE_NBR,
            QSRP.TAX_ID,QSRP.ROW_ID;

为此尝试用HAVING而不是qualify，但出现错误：

ORA-00904：“ MAX_SO_DTM”：无效的标识符00904。00000-“％s：无效的标识符”

似乎用于MAX的别名在这里无法使用...。

非常感谢您的帮助！

编辑：

SELECT * FROM
  (         
 SP.ID,
     SP.SO_DTM,
     SP.TAX_ID,
     SP.USER_ID,
     SP.FRST_NM,
     SP.LAST_NM,
     SP.PHONE_NBR,
     QSRP.TAX_ID,
     QSRP.ROW_ID,
     MAX(SP.SO_DTM) OVER (PARTITION BY SP.ID, SP.TAX_ID) AS MAX_SO_DTM       
FROM VOPR_RMSY SP,VOPR_RMSY_SPNS QSRP 
WHERE  SP.ID =:URVYID AND QSRP.TAX_ID =:RPAXID AND SP.ID = QSRP.ID AND SP.TAX_ID =  
       QSRP.TAX_ID AND SP.SO_DTM = QSRP.SO_DTM 
GROUP BY SP.ID,SP.SO_DTM,SP.TAX_ID,SP.USER_ID,SP.FRST_NM,SP.LAST_NM,SP.PHONE_NBR,
        QSRP.TAX_ID,QSRP.ROW_ID;
 )dt WHERE (SP.SO_DTM=MAX_SO_DTM AND QSRP.SO_DTM = MAX_SO_DTM) 

我知道我必须对外部WHERE而不是SP和QSRP使用别名dt，但是在这里将MAX_SO_DTM与来自两个不同表的SO_DTM进行了比较。还有其他方法可以修改吗？

谢谢！

Answer 1

QUALIFY和重用别名都是特定于Teradata的。

您尝试使用HAVING失败，因为这是处理查询的逻辑顺序：

FROM
WHERE
GROUP BY
HAVING
OLAP-function
QUALIFY -- Teradata specific
SAMPLE or EXPAND ON  -- both are Teradata specific
ORDER

若要解决此问题，您必须使用“派生表/内联视图”并将“合格”条件移到外部WHERE中。

SELECT *
FROM
 (
   SELECT S.ID  as Id,
          S.MP_CD as Code,
          S.GM_CD  as GmCode,
          S.GM_MSR_NBR as Mea_Year, 
          S.STTS_CD as YearCode,
          S.TRMNTN_DTM as TerminationDate,
          ROW_NUMBER () OVER (PARTITION BY S.GM_CD ,S.MP_CD ,S.GM_MSR_NBR,S.STTS_CD 
                          ORDER BY S.SO_DTM DESC) AS rn 
     FROM PD.RVY S, LOAD_LOG TLL 
    WHERE S.UPDTD_LOAD = TLL.LOG_KEY AND TLL.BLSH_CD = 'Y' AND S.STTS_CD IN ( 'C', 'P' ) 
  ) dt
WHERE rn = 1;

当您要重用别名时，必须使用相同的技术。

编辑：第二查询可以重写为：

SELECT * 
FROM
 (        
   SELECT 
        SP.ID,
        SP.SO_DTM,
        SP.TAX_ID,
        SP.USER_ID,
        SP.FRST_NM,
        SP.LAST_NM,
        SP.PHONE_NBR,
        QSRP.TAX_ID,
        QSRP.ROW_ID,
        MAX(SP.SO_DTM) OVER (PARTITION BY SP.ID, SP.TAX_ID) AS MAX_SO_DTM       
   FROM VOPR_RMSY SP,VOPR_RMSY_SPNS QSRP 
   WHERE SP.ID =:URVYID 
     AND QSRP.TAX_ID =:RPAXID 
     AND SP.ID = QSRP.ID 
     AND SP.TAX_ID =  QSRP.TAX_ID 
     AND SP.SO_DTM = QSRP.SO_DTM
   GROUP BY SP.ID,SP.SO_DTM,SP.TAX_ID,SP.USER_ID,SP.FRST_NM,SP.LAST_NM,SP.PHONE_NBR,
           QSRP.TAX_ID,QSRP.ROW_ID
 )dt
WHERE SO_DTM=MAX_SO_DTM 

您不需要进行两个比较*（SP.SO_DTM = MAX_SO_DTM AND QSRP.SO_DTM = MAX_SO_DTM）*，因为在* SP.SO_DTM = QSRP.SO_DTM *上连接了表时，它们的第二个比较多余。

否则，您必须使用其他别名（例如QSRP_SO_DTM）将QSRP.SO_DTM添加到派生表中。在外层，没有更多的SP / QSRP，只有dt，所以它将是：

WHERE (SO_DTM=MAX_SO_DTM AND QSRP_SO_DTM = MAX_SO_DTM)