SQL Syntax - response (1) by ulrich

did you try to create a view like

Create view VW2 as 
SEL a.col1, 
    a.col2, 
    a.col3, 
    b.col4 
from 
( sel col1, 
      col2, 
      col3 
   from tab1 
   where col2 = 'ABC'
) a
left outer join
(SEL col1, 
     Col3 as col4 
 from tab1 
 where col2 = 'ABC'
 qualify row_number() over ( order by col1) = 1
) b 
on a.col1 = b.col1;

If yes, what had been the issue?
If no, what had been preventing you from doing so?