How to concatenate more than two rows n mysql

If you have the table called "table1" with following data,

fID field1
1   Data1
2   Data2
3   Data3

and you want data in one row like: 
Data1, Data2, Data3

then you can use the following query:

select fID, group_concat(field1 separator ', ')  from table1 group by fID;