For example, from this table
| row | col | val |
|---|---|---|
| 0 | A | 32 |
| 0 | B | 31 |
| 0 | C | 35 |
| 1 | A | 30 |
| 1 | B | 29 |
| 1 | C | 29 |
| 2 | A | 15 |
| 2 | B | 14 |
| 2 | D | 18 |
| 3 | A | 34 |
| 3 | B | 39 |
| 3 | C | 34 |
| 3 | D | 35 |
it should produce this table:
| A | B | C | D | |
|---|---|---|---|---|
| 0 | 32 | 31 | 35 | |
| 1 | 30 | 29 | 29 | |
| 2 | 15 | 14 | 18 | |
| 3 | 34 | 39 | 34 | 35 |
Is there some official, canonical (or at least popular specific unambiguous) term for such operation (or its reverse)?
I am trying to find (or implement & publish) a tool that transforms CSV this way, but am unsure what to search for (or how to name it).
CodePudding user response：
The term is pivot.
Some databases have native support for pivot, eg SQL Server's PIVOT (and even UNPIVOT) keywords.
For most databases you must craft a query that does the job.