sql - How to transpose multiple rows into multiple columns?

Question

Grouping col_1 in ascending values of seq column to display values from comment columns in multiple columns for below sample data:

col_1  |  Seq  |  Comment |
--------------------------|
ABC    |   30  |  TestC   |
ABC    |   50  |  TestE   |
ABC    |   80  |  TestG   |
ABC    |   10  |  TestA   |
ABC    |   60  |  TestF   |
ABC    |   20  |  TestB   |
ABC    |   70  |  TestF   |
ABC    |   40  |  TestD   |
DEF    |   20  |  TestB   |
DEF    |   10  |  TestA   |
GHI    |   10  |  TestA   |
--------------------------|

Expected output of sql should be:
Col_1  | Col_2 | Col_3 | Col_4 | Col_5 | Col_6 | Col_7 | Col_8 | 
-------|-------|-------|-------|-------|-------|-------|-------|
ABC    | TestA | TestB | TestC | TestD | TestE | TestF | TestG |
DEF    | TestA | TestB |       |       |       |       |       |
GHI    | TestA |       |       |       |       |       |       |
-------|-------|-------|-------|-------|-------|-------|-------|

标签： sqloracleoracle11gpivot

Answer 1

您可以使用条件聚合和row_number()：

select col_1,
       max(case when seqnum = 1 then comment end) as col_2,
       max(case when seqnum = 2 then comment end) as col_3,
       max(case when seqnum = 3 then comment end) as col_4,
       . . .
from (select t.*,
             row_number() over (partition by col_1 order by seq) as seqnum
      from t
     ) t
group by col_1;