How to concatenate multiple cell data into a single cell based on condition using SQL

New to using SQL here. I use Amazon Athena.

For example, say I have a table, customer_svc, of customers and the services they've subscribed to as follows:

I need to design a query to concatenate the services for each unique customer into a single string as follows:

customer	services
Alex	A, B, C
Dave	A, D

Any help would be much appreciated.

Solution

Tested in Amazon Athena / S3 :

Dataset used for the query exmaple

Query

select customer, array_join(array_agg(service),',') as services from customer_svc group by customer

Results

Arrays documentation