Question

I have a Column 1 which in this case is the same value repeating through all the rows. Column 2 has non distinct rows in which values may repeat. I want to create a column named Group to show that the rows belong to this group in seqential order (Ordered by Column 2). Basically, I need to create an output that looks similar to this:

Column 1   | Column 2   | Group
--------------------------------
100        | AA         | 1
100        | AA         | 1
100        | AA         | 1 
100        | BB         | 2
100        | BB         | 2
100        | CC         | 3
100        | DD         | 4
100        | DD         | 4

Answer 1

You could use the dense_rank function in oracle.

select col1,
       col2,
       dense_rank () over (partition by col1
                         order by col2) group_column
  from test_table;

      COL1 CO GROUP_COLUMN
---------- -- ------------
       100 AA            1
       100 AA            1
       100 AA            1
       100 BB            2
       100 BB            2
       100 CC            3
       100 DD            4
       100 DD            4

You could use “order by col1, col2” to verify the results.