AWS Athena 创建二进制矩阵

Question

Is it possible to create a binary matrix in AWS Athena from a table. For example we have the following table:

name	product
John	Bike
John	Shirt
John	Ball
Blake	Shirt
Mike	Ball
Mike	Hat

To be converted to the following:

name	Bike	Shirt	Ball	Hat
John	1	1	1	0
Blake	0	1	0	0
Mike	0	0	1	1

Answer 1

I suggest you to use Case expression:

select name, 
sum(case when product = 'bike' then 1 else 0 end) as "Bike",
sum(case when product = 'Shirt' then 1 else 0 end) as "Shirt",
sum(case when product = 'Ball' then 1 else 0 end) as "Ball",
sum(case when product = 'Hat' then 1 else 0 end) as "Hat"
from tableName