nested joins check

[jobo]

Well, I never understood why people neglegt formating in SQL Statements. Looks a little like masochism. There are even online tools for formatting SQL statements. The suggestion above was done automatically and pimped a little by hand, a matter of seconds.

And I don't know anything about QDA9, but with reference to the naming, You don't have to start with changing column definitions.
Just make use of views. Not only to rename columns, use them as interface. It's so simple!

Code:

create view GetUsefulNames as
select 
  column3 as Useful_PKID,
  column1 as Useful_Name,
  column2 as Useful_Quantity,
  column9 as Useful_Class,
  trim(column8) as Useful_AlwaysClean_Code
  ..
  from dat_messung

You can use it vor any Report and other stuff within your control. And you could pass it to others.
The use of views in oracle is quite powerful, you can even update, as long as the pk Column is included. Even my example would be updatable would be updatable except the trimmed column.

Of course You could add a restriction there in any view, limiting view result to certain criteria. And you can update even this views containg a where clause (But caution, you can do uptdates violating the criterias, use an extra clause in where condition to prohibit conflicting updates)

And if you know it is and will be a reporting view in future, You can do a lot of preprocessing in some baseline views.

Just give it try as soon as soon as You got a little picture of the things in the new "Firma".