select id1,id2 from your_table where id2>=id1
union
select id2,id1 from your_table where id2<id1;
should work
From: Shaozhong SHI <shishaozhong@gmail.com>
Sent: Monday, October 24, 2022 4:44 PM
To: pgsql-sql <pgsql-sql@lists.postgresql.org>
Subject: select only 1 pair
There are pair ids. Each pair is repeated. id1 id2 1 2 2 1 3 4 4 3 How to only select 1 unique pair for each? Regards, David
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There are pair ids. Each pair is repeated.
How to only select 1 unique pair for each?
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