With some WHERE clause criteria, have SQL output go to next line - sql

Question

I am trying to write a query where I have some criteria where I pivot the results. However, due to output file constraints I am looking for the output to create a new line after the pivot exceeds X, even if the ID and such is otherwise the same.
What I am trying to do:
|--ID--|-Value-|
| 1 | val1 |
| 1 | val2 |
| 1 | val3 |
| 2 | val1 |
|--ID--|-Col1-|-Col2-|
| 1 | Val1| Val2|
| 1 | Val3| |
| 2 | Val1| |
SELECT *
FROM table
PIVOT(max(value) for field1 in (t1,t2)
as pvt
ORDER BY UNIQUE_ID
This is just a pivot example to pivot this particular column. However the output has a very strict number of column requirement so I'd be looking for any pivot beyond the 5th to "overflow" to the next row while retaining the unique id. I am looking at PIVOT but I dont think it will work here.
Is this even possible within the Snowflake platform or do I need to explore other options?

Answer 1

This requirement is purely presentation matter and in my opinion should not be performed at the database level. With that being said it is possible to achieve it by numbering rows in group and performing modulo division:
Samle data:
CREATE OR REPLACE TABLE tab
AS
SELECT 1 AS id, 'val1' AS value UNION
SELECT 1 AS id, 'val2' AS value UNION
SELECT 1 AS id, 'val3' AS value UNION
SELECT 2 AS id, 'val1' AS value;
Query:
WITH cte AS (
SELECT *, ROW_NUMBER() OVER(PARTITION BY id ORDER BY value) - 1 AS rn
FROM tab
)
SELECT
id
,MAX(CASE WHEN rn % 2 = 0 THEN value END) AS col1
,MAX(CASE WHEN rn % 2 = 1 THEN value END) AS col2
FROM cte
GROUP BY id, FLOOR(rn / 2)
ORDER BY id, FLOOR(rn / 2);
Intermediate result:
WITH cte AS (
SELECT *, ROW_NUMBER() OVER(PARTITION BY id ORDER BY value) - 1 AS rn
FROM tab
)
SELECT id,value, rn, FLOOR(rn / 2) AS row_index, rn % 2 AS column_index
FROM cte
ORDER BY ID, rn;
Generalized:
WITH cte AS (
SELECT *, ROW_NUMBER() OVER(PARTITION BY id ORDER BY value) - 1 AS rn
FROM tab
)
SELECT
id
,MAX(CASE WHEN rn % N = 0 THEN value END) AS col1
,MAX(CASE WHEN rn % N = 1 THEN value END) AS col2
-- ....
,MAX(CASE WHEN rn % N = N-1 THEN value END) AS colN
FROM cte
GROUP BY id, FLOOR(rn / N)
ORDER BY id, FLOOR(rn / N);