Pivot table in SQL with multiple columns

Question

I have this data

ID  Month   PRODUCT VALUE_1 VALUE_2
1234    1   a        34 12
1233    2   B        54 
1245    3   c        23 42
1236    4   d        12 8
1238    1   a        56 5
1239    2   B        42 1
1234    3   c        32 6
1233    4   d           3
1245    1   a        8  6
1236    2   B        5  2
1238    3   c        1  6
1239    4   d        2  
1234    1   a        15 4
1233    2   c        8  12
1245    3   d        15 6
1236    4   b         1 1
1238    1   c        14 10
1239    2   d        13 6
1234    3   c        13 17
1233    4   b        15 5
1245    1   c        18 11
1236    2   d        12 15
1238    3   c        8  12
1239    4   a       17  4

and trying to reach to this:

SUM   a                 b               c               d           
ID    a_1   a_2 a_3 a_4 b_1 b_2 b_3 b_4 c_1 c_2 c_3 c_4 d_1 d_2 d_3 d_4
1233    0   0   0   0   0   54  0   15  0   8   0   0   0   0   0   0
1234    49  0   0   0   0   0   0   0   0   0   45  0   0   0   0   0
1236    0   0   0   0   0   5   0   1   0   0   0   0   0   12  0   12
1238    56  0   0   0   0   0   0   0   14  0   9   0   0   0   0   0
1239    0   0   0   17  0   42  0   0   0   0   0   0   0   13  0   2
1245    8   0   0   0   0   0   0   0   18  0   23  0   0   0   15  0

Basically, I want to see each product value aggregated for each month;

In python would be the equivalent to, just one line of code.

data.pivot_table(index=['ID'], columns=["Product","Month"],
                            values=["Value_1","Value_2"], 
                            aggfunc=np.sum, 
                            dropna = False, fill_value=0)

I've tried this:

WITH pivot_table as (SELECT * FROM
(
SELECT ID, PRODUCT,Value_1,Value_2, Month  
FROM DATASET  
) New_dataset
PIVOT (
    --#2 aggregation
    SUM(Value_1) as value1 , SUM(Value_2) as value2
    --#3 Pivot_column
    FOR PRODUCT IN ('a','b','c','d') 
))
#as pivot_table
SELECT ID ,Month, SUM(value1_a) as a_1, SUM(value2_a) as a_2 FROM pivot_table
GROUP BY ID, Month
ORDER BY value_1

I've got so far to this table, which ignores the blanks, and still needs to be transposed

 ID     MONTH  value1_a
1234    1      49
1238    1      56
1239    4      17
1245    1      8

But I will still need to run for all the others and concatenate? or do i have to write all the products? and then transpose? SQL might be able to do this in one go right? or am I thinking to much on python way?

Answer 1

I will still need to run for all the others and concatenate? or do i have to write all the products? and then transpose? SQL might be able to do this in one go right?

Below solution makes it

execute immediate (             
select '''select * from (select id, lower(product) || '_' || month product_month, value_1 from `project.dataset.table`)
  pivot(sum(value_1) for product_month in ("''' ||  string_agg(product_month, '", "')  || '''"))
  order by id
'''
from (
  select product || '_' || month product_month 
  from (select distinct lower(product) product from `project.dataset.table`)
  cross join (select distinct month from `project.dataset.table`) 
  order by product_month) 
);

If applied to sample data in your question - output is