For a union to work you should have the same count and type of columns in the select statement.
As far as I can see there are a couple of things you can set right.
First. You cannot convert NULL to number. So remove the To_number conversion. NULL is acceptable datatype which can be mixed with...
This site uses cookies to help personalise content, tailor your experience and to keep you logged in if you register.
By continuing to use this site, you are consenting to our use of cookies.