0 - 3 of 3 tags for #teradata #database #query #analytical#analytical functions

Hi,
I am unable to get the intended result table.
I have the following table:
ORDERSERIALNO     USERID       PRODSKU         PRODUCTTABLE       NETREVENUE     ORDERPLACEDTIME          
123-345                   123            PHOTO01           CARDS                            44                  31OCT2010                  

I am new to Teradata. I have to solve below problem using SQL/Stored procedure in Teradata.
Problem - As shown in below input data, We need to link the records in the table by the values of Col1 and Col2.
Logic - For all set of records which are having linking values of col1 and col2 should have min(col1) as col3.

Dear Folks,
I have a table with information like subscriber added/removed particular feature along with the date it added or removed. Also if he is active or canceled his subscription.