I need a solution to display data using PostgreSQL [closed]

Question

Col_1         Col_2
====================
A              
B              A
C              B
D              A
E              D
F              B

Result required in this way:

Col_1       Col_2
=================
A            B
A            D
B            C
B            F
D            E

This is not a forum to test the readability of obfuscated code. You need to explain the problem to a human.
so? show us what you've tried. At least show us the SQL that got you the first result. Have you tried order by col_1? Or perhaps order by col_1, col_2?
yeah I tried order by Col_1, Col_2. But, I didn't get suitable result.
Hi Suresh, I am not testing anybody with my obfuscated code. I am new to query language.
What about table structure, sample data? Is the first list actual table data in a single table?

Stefan Steinegger · Answer 1 · 2012-09-27 11:11:36Z

up vote 0 down vote

From all I know about your problem (that is what you write in the question), the following will produce the requested result:

SELECT 
  Col_2 as Col_1,
  Col_1 as Col_2
FROM table
WHERE Col_2 IS NOT NULL
ORDER BY Col_2, Col_1

answered Sep 27 '12 at 11:11

Stefan Steinegger
30k142109

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closed as not a real question by bažmegakapa, ronalchn, HaskellElephant, John Conde, hochl Sep 27 '12 at 11:28