Using GatherBy with a DataSet's header designation instead of First

Question

Using the code, where ds is data formatted into a Dataset

GroupBy[ds, First] // TableForm

I get a table that I wanted, but I was wondering if I could somehow use the header of my dataset to designate which column to group by.

I just want to guard against a file generating some data and the first column not being the one I want to group my data by.

If we call the name of the column "name", I would like to do something to the tune of

GroupBy[ds, name] // TableForm

Answer 1

ds[GroupBy[#name&]] (* or *)
GroupBy[#name&][ds] (* or *)
GroupBy[ds, #name&]

Answer 2

Here is another form that may be a bit easier to work with than the Slot form in kguler's answer:

ds = Dataset[{
   <|"a" -> 1, "b" -> "x", "c" -> {1}|>,
   <|"a" -> 2, "b" -> "y", "c" -> {2, 3}|>,
   <|"a" -> 3, "b" -> "z", "c" -> {3}|>,
   <|"a" -> 4, "b" -> "x", "c" -> {4, 5}|>,
   <|"a" -> 5, "b" -> "y", "c" -> {5, 6, 7}|>,
   <|"a" -> 6, "b" -> "z", "c" -> {}|>}]

ds[GroupBy["b"]]

You could also use Extract:

ds ~GroupBy~ Extract["b"]

In either case if the name is not a string add Key.