concatenate data from column year when GROUP BY on Column Amount (MySQL)

I have a table from which I generate a view Grouping By Year and summing the amounts, and I wonder if I could somehow include a "string sum" or "string concatenation" of the aggregated dates or months. Example: this is the base table ID | date | year | month | amount This is the actual view ID | year | sum(amount) what I am looking for is an additional field with concatenates the months to 03,05,11 (for example or to something similar), if a year aggregates data from march, may and november ID | year | sum(amount) | list_of_months Is that possible or do I have to create helping views to aggregate that? Edit: I was able to answer myself: Group_concat to the help as shown in the answer below