KQL change order of columns in evaluate pivot

Question

I have the following query:

let fooTable = datatable(TIMESTAMP: datetime, list_id: int, dim_count: int) [
    datetime("2022-01-17T08:00:00Z"), -1, 120,
    datetime("2022-01-17T08:00:00Z"), 1, 50,
    datetime("2022-01-17T08:00:00Z"), 2, 30,
    datetime("2022-01-17T08:00:00Z"), 8, 30,
    datetime("2022-01-17T08:00:00Z"), 2001, 30,
    datetime("2022-01-17T08:00:00Z"), 4, 30,
];
fooTable
| order by TIMESTAMP desc, dim_count desc 
| evaluate pivot(list_id, take_any(dim_count), TIMESTAMP)

Answer 1

If the order is based on the row_number , you can use it with the project-reorder operator, the client will need to parse the column names and remove the prefix, for example:

let fooTable = datatable(TIMESTAMP: datetime, list_id: int, dim_count: int) [
    datetime("2022-01-17T08:00:00Z"), -1, 120,
    datetime("2022-01-17T08:00:00Z"), 1, 50,
    datetime("2022-01-17T08:00:00Z"), 2, 30,
    datetime("2022-01-17T08:00:00Z"), 8, 30,
    datetime("2022-01-17T08:00:00Z"), 2001, 30,
    datetime("2022-01-17T08:00:00Z"), 4, 30,
];
fooTable
| serialize 
| extend list_id = strcat(row_number(), "_", list_id)
| order by TIMESTAMP desc, dim_count desc 
| evaluate pivot(list_id, take_any(dim_count), TIMESTAMP)
| project-reorder *

TIMESTAMP	1_-1	2_1	3_2	4_8	5_2001	6_4
2022-01-17 08:00:00.0000000	120	50	30	30	30	30