Query to join 2 columns of same table

Question

I have a table txn(id,orig_num,rec_num)

How to write a query to return distinct values present in both column? I want to join these two columns (orig_num and rec_num) and return 1 column (say acct_num) which will have distinct account numbers. I am using sql server

Answer 1

select orig_num as acct_num from your_table
union
select rec_num from your_table

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