Hi,

I have a data set like this:

col1 , col2
------------
'A' , 'aa'
'A' , 'bb'
'A' , 'cc'
'B' , 'dd'
'B' , 'ee'

By using grouping, currently we have aggregate functions like: sum(...), avg(...), etc...
But sum(...) is to sum all number values. Do we have any function or any way to 'sum' the String values?

For example, based on the data set above, i want to retrieve the concat string like this (after grouping col1):
'A': 'aabbcc'
'B': 'ddee'

I heard that there is a function called 'group_concat' in mysql, do we have similar function in HQL?