填充同一列中其他数据的值 (Teradata)

Question

我有一个查询结果的表（它很大！），看起来像这样。

表试图按类型计算每个 id 中的一组名称（seq_num 1,2..），但当不同类型出现在同一个 id 中时，它会留下零

我想得到一个看起来像这样的结果。

不能使用 subquery 或 max ，因为这需要 group by ，因为查询已经太复杂了。

非常感谢这里的一些帮助。 谢谢！

最右边那四列的查询代码：

CASE WHEN (TYPE = 'E') THEN (DENSE_RANK() OVER (PARTITION BY ID,TYPE ORDER BY NAME) + DENSE_RANK() OVER (PARTITION BY ID, TYPE ORDER BY NAME DESC) - 1) ELSE 0 END AS NC_E,

CASE WHEN (TYPE = 'M') THEN (DENSE_RANK() OVER (PARTITION BY ID,TYPE ORDER BY NAME) + DENSE_RANK() OVER (PARTITION BY ID, TYPE ORDER BY NAME DESC) - 1) ELSE 0 END AS NC_M,

CASE WHEN (TYPE = 'D') THEN (DENSE_RANK() OVER (PARTITION BY ID,TYPE ORDER BY NAME) + DENSE_RANK() OVER (PARTITION BY ID, TYPE ORDER BY NAME DESC) - 1) ELSE 0 END AS NC_D,

CASE WHEN (TYPE = 'C') THEN (DENSE_RANK() OVER (PARTITION BY ID,TYPE ORDER BY NAME) + DENSE_RANK() OVER (PARTITION BY ID, TYPE ORDER BY NAME DESC) - 1) ELSE 0 END AS NC_C

注意：我有其他 ID，其中 TYPE 没有改变，而且它工作正常，我可以理解为什么会这样。问题在于每个 ID 中的信息非常多样化。

Answer 1

您想要一个COUNT(DISTINCT Name) OVER (PARTITION BY ID, TYPE)，Teradata 不支持它。

最有效的方法是嵌套的 OLAP 函数，这将导致两个 STAT 步骤，就像您当前的解决方案一样，所以这应该不会降低效率：

SELECT dt.*,
    Max(CASE WHEN type = 'E' THEN nc END) Over (PARTITION BY id) AS NC_E
   ,Max(CASE WHEN type = 'M' THEN nc END) Over (PARTITION BY id) AS NC_M 
   ,Max(CASE WHEN type = 'D' THEN nc END) Over (PARTITION BY id) AS NC_D 
   ,Max(CASE WHEN type = 'C' THEN nc END) Over (PARTITION BY id) AS NC_C 
FROM
 ( 
   SELECT ....
      Dense_Rank() Over (PARTITION BY ID, TYPE_ ORDER BY NAME) AS nc
   FROM ...
 ) AS dt