How to remove duplicates from comma separated list by regex in Oracle regexp_replace? [duplicate]

Answer 1

Select replace(REGEXP_REPLACE('1234567890,2220006789,2220006789,477-000-6789','([^,]+)(,[ ]*\1)+'),',,',',') 
As [columnName] From [tableName]

Answer 2

([^,]+)(,[ ]*\1)+

Try this.This works.See demo.

http://regex101.com/r/yG7zB9/8

The issue was VA - HRD 1, VA - HRD 1

                     ^  ^

The space here.You were not taking this into account as the first match has no space behid it.So inlcde [ ]* or \s* to make it accept.