getting a comma separated list in a MySQL Group By statement

If you are combining several rows in a MySQL query using a GROUP BY statement and still want to get a comma separated list of all the values of a particular column…

something like below:

Dataset:

ID           Marks

1                 20

2                 30

3                 40

Result Required:

IDs         Sum(Marks)

1,2,3          90

you should be using the GROUP_CONCAT function of MySQL. Check out more of it at MySQL official documentation