When working with data with the intent to visualize, there are times when I'll want to group by every column in a table, separately, one at a time, to determine the possible values in that column.
I do this often enough I created a simple SQL Query to build these group by statements for me:
declare @table_name varchar(200) = 'dbo.mytablename'
'select ' + c.name + ', count(1) cnt from ' + @table_name + ' group by ' + c.name + ' order by 2 '
from sys.columns c
where c.object_id = object_id(@table_name)
Hope this helps,