How to order the records from different records with matching data in two differents columns as continous rows in output

Question

Need help with Oracle query which will provide the output in below the format.

Sample table

c1 c2 c3 c4
-- -- -- -- 
 A  1 A1
 B  2 B1 C1
 D  6 E2 A1
 A  2    A1
 C  3 C1
 D  4 D1 E1

I want to join same table where data in 3rd Column matches the data in 4th and expecting the data to be sorted as subsequent records as below

c1 c2 c3 c4
-- -- -- -- 
 A  1 A1
 A  2    A1
 D  6 E2 A1
 B  2 B1 C1
 C  3 C1

Answer 1

That's not a grouping, it's a sorting that you need:

select *
from your_table
order by coalesce(col1,'ZZZ') desc, 
                  col2 desc --coalesce will use 'ZZZ' to order if column is null