Question

您好我想在Teradata V14 sql中做。我的源表是这样的：

New_Col1 New_Col2 Acc col1 col2

1          1      100  12     13
2          1      100  13     14
3          2      100  17     23
4          3      100  22     109
5          3      100  23     110
6          4      100  29     130

我的目标表应为：

{{1}}

New_Col1 - 行号 New_Col2 - 如果col1和col2顺序相同，则应为New_COl2。否则应生成新的序列号能帮助我实现这一目标。

Answer 1

您需要嵌套的OLAP函数：

SELECT dt.*,
   sum(flag) 
   OVER (PARTITION BY acc
         ORDER BY new_col1
         ROWS UNBOUNDED PRECEDING)
FROM
 (
   SELECT t.*,
      ROW_NUMBER() OVER (PARTITION BY acc ORDER BY col1, col2) AS new_col1,
      CASE WHEN col1 = MIN(col1) -- col1 is sequential
                       OVER (PARTITION BY acc
                             ORDER BY col1,col2
                             ROWS BETWEEN 1 PRECEDING AND 1 PRECEDING) + 1
            AND col2 = MIN(col2) -- col2 is sequential
                       OVER (PARTITION BY acc
                             ORDER BY col1,col2
                             ROWS BETWEEN 1 PRECEDING AND 1 PRECEDING) + 1
           THEN 0 -- will be assigned to the previous group
           ELSE 1 -- will be assigned to a new group
      END AS flag   
   FROM tab AS t
 ) AS dt

Answer 2

看起来第二个新列只是 col1 是否按顺序排列。您可以使用row_number()：

执行此操作

select row_number() over (partition by acc order by col1),
       dense_rank() over (partition by acc order by grp),
       acc, col1, col2
from (select t.*,
             (col1 - row_number() over (partition by acc order by col1)) as grp
      from t
     ) t;

根据另一个列排序生成新列 - SQL

2 个答案: