Question

I have two tables which I would like to place side-by-side exactly as they are. For example,

tableOne                              tableTwo
columnOne | columnTwo | columnThree   columnI | columnII | columnIII

The data in the two tables do not need to be related whatsoever — the tables have the same row count — and the data is already sorted in the two tables. Basically, I would like to do a full outer join on the two tables without an on operator.

How can I do this in a SQL query?

Answer 1

Well, you do want an ON operator – you just seem to want it to work automatically, which won’t happen.

If you’re saying Row 1 of tableOne maps to Row 1 of tableTwo, then you need to add a row column to each table and then join on it.

If you don’t specify a join condition, you’ll do a cross join that joins every row from tableOne to every row in tableTwo, which obviously isn’t what you’re looking for.

So do something like this:

select * from 
  (select *, row_number() over (order by 1) as RN from tableOne) a
  inner join (select *, row_number() over (order by 1) as RN from tableTwo) b
     on a.RN = b.RN