SQL table function that returns one of two different select statements?

[Vectorspace]

I have an SQL table function, where I wanted to do effectively this:

if a = 1 then
  return
    select a,b,c from table1 where e=f;
else then
  return
    select a,b,c from table2 where e=f;​
end if;

Based on some earlier logic or parameter, return results from one table or another table.

But it would not let me have two return statements, So in the end I did this:

  return
    select a,b,c from table1 where e=f and a = 1
    union all
    select a,b,c from table2 where e=f and a <> 1;​

Union both tables, and condition each on the earlier logic so one of the two will always return nothing.

Is there a better way?

I now know I could have opened the required select in a cursor and piped it to the return (I didn't know about PIPE when I wrote this), but that seems more complicated as I would need to define two cursor loops.

[B.Hauser]

Define 2 Cursors - Depending on the condition read the first or the second cursor and return the rows with the PIPE Statement

[Vectorspace]

Awww I hoped there was a neater way

Thanks as always Birgitta!