I have a table that is using UNIQUEIDENTIFIER pk values. There is another character field that has duplicate values in it.

For example (using integer pks for simplicity)

PK   Value
1    a
2    b
3    a
4    c
5    a

I want a query that will give me the first PK value for each unique "Value". So I will get back:

PK
1
2
4

How can I do this?