postgresql - Remove the repetitive row by checking different column -


i have data sample such below :

set of data

how can postgresql eliminate duplicate row check column1 , column2 @ different row ? doing normal comparison still unlucky @ time. hope may share idea.

select d1.* distance d1 not exists (select 1                   distance d2                   d1."from" = d2."to"                     , d1."to" = d2."from"                     , d2."from" < d2."to"                  );

if there “duplicate”, query pick row "from" < "to".


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