Dynamic Pivoting in SQL - Snowflake - sql

Question

I have an input file
Customer PhoneNum Location Brand
John 1234 ABC Oppo
John 1234 DEF MI
John 1234 KLM RealMe
John 1234 LKM 1+
Joe 9934 ABC Apple
Joe 9934 DEF Samsung
The same phone number can be listed to multiple phone brands and the number of brands per phone number can be dynamic i.e. some can have 2 brands some can have 4 some 8 etc. I can pass the list of unique brands in the pivot query but that would create columns which might not have values.
the result i want is
Customer PhoneNum Brand1 Brand1Location Brand2 Brand2Location Brand3 Brand3Location Brand4 Brand4Location
John 1234 Oppo ABC MI DEF RealMe KLM 1+ LKM
Joe 9934 Apple ABC Samsung DEF
```
Here i dont need the list of brands but if i know the maximum record per number is say 4 i can have the output in above format, which I believe is a good way to read the result.
Is there any way in SQL to get the above result.
select * from phone_multiple_make
pivot(max(location),max(brand) for brand in
('MI','Oppo','RealMe') )as p;

Answer 1

If you're ok with not using a pivot function you can acheive your results like this:
WITH CTE AS (
SELECT 'John' CUSTOMER,1234 PHONENUM,'ABC' LOCATION,'Oppo' BRAND
UNION
SELECT 'John' CUSTOMER,1234 PHONENUM,'DEF' LOCATION,'MI' BRAND UNION
SELECT 'John' CUSTOMER,1234 PHONENUM,'KLM' LOCATION,'RealMe' BRAND UNION
SELECT 'John' CUSTOMER,1234 PHONENUM,'LKM' LOCATION,'1+' BRAND UNION
SELECT 'Joe' CUSTOMER,9934 PHONENUM,'ABC' LOCATION,'Apple' BRAND UNION
SELECT 'Joe' CUSTOMER,9934 PHONENUM,'DEF' LOCATION,'Samsung' BRAND )
SELECT CUSTOMER, PHONENUM
,J:BRAND1:BRAND::STRING BRAND1, J:BRAND1:LOCATION::STRING LOCATION1
,J:BRAND2:BRAND::STRING BRAND2, J:BRAND2:LOCATION::STRING LOCATION2
,J:BRAND3:BRAND::STRING BRAND3, J:BRAND3:LOCATION::STRING LOCATION3
,J:BRAND4:BRAND::STRING BRAND4, J:BRAND4:LOCATION::STRING LOCATION4
FROM (
SELECT CUSTOMER, PHONENUM, OBJECT_AGG(KEY,OBJ) J FROM (
SELECT CUSTOMER, PHONENUM
,'BRAND'||ROW_NUMBER()OVER(PARTITION BY CUSTOMER,PHONENUM ORDER BY BRAND)::STRING KEY
,OBJECT_CONSTRUCT( 'LOCATION', LOCATION, 'BRAND',BRAND) OBJ FROM CTE) GROUP BY 1,2)