Question

我试图解决这个SQL问题。例如我有这个：

 A1              TIER        DATE
TRY10,49         Tier 7      01/01/2013 
TRY104,99        Tier 51     01/07/2015 
TRY104,99        Tier 54     01/01/2013 
TRY1049,99       Tier 84     01/01/2013 
TRY11,19         Tier 6      01/01/2013 
TRY111,99        Tier 55     01/01/2013 
TRY111,99        Tier 52     01/07/2015

当一行的A1等于另一行的A1时，我想只选择层数较小的行。

例如，第二行的A1等于第三行的A1。所以我只想要第二行，因为第51层＆lt;第54层。

因此查询应该成为：

 A1              TIER      DATE
TRY10,49         Tier 7    01/01/2013       
TRY104,99        Tier 51   01/07/2015    
TRY1049,99       Tier 84   01/01/2013   
TRY11,19         Tier 6    01/01/2013   
TRY111,99        Tier 52   01/07/2015

Answer 1

使用此查询：

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Answer 2

试试这个

4096x4096x4096

Answer 3

您可以尝试此查询。这足以满足你的条件。

SELECT b.nm,
  b.tr,
  b.dt
FROM
  (SELECT a.nm,
    a.tr,
    a.dt,
    row_number() over(partition BY a.nm order by to_number(trim(SUBSTR(a.tr,5,LENGTH(a.tr))))) rnk
  FROM
    (SELECT 'TRY10,49'      AS nm,
      'Tier 7'              AS tr,
      to_date('01/01/2013') AS dt
    FROM dual
    UNION
    SELECT 'TRY104,99'      AS nm,
      'Tier 51'             AS tr,
      to_date('01/07/2015') AS dt
    FROM dual
    UNION
    SELECT 'TRY104,99'      AS nm ,
      'Tier 54'             AS tr,
      to_date('01/01/2013') AS dt
    FROM dual
    UNION
    SELECT 'TRY1049,99'     AS nm,
      'Tier 84'             AS tr,
      to_date('01/01/2013') AS dt
    FROM dual
    UNION
    SELECT 'TRY11,19' AS nm, 'Tier 6' AS tr, to_date('01/01/2013') AS dt FROM dual
    UNION
    SELECT 'TRY111,99'      AS nm,
      'Tier 55'             AS tr,
      to_date('01/01/2013') AS dt
    FROM dual
    UNION
    SELECT 'TRY111,99'      AS nm,
      'Tier 52'             AS tr,
      to_date('01/07/2015') AS dt
    FROM dual
    )a
  )b
WHERE b.rnk = 1;

仅选择具有相同字段的两行

3 个答案: