Questions about updateable views

Question

Greetings,
Some problems which I experienced with Delphi + Crlab ODAC + Oracle DB 10g Express and complex (joined tables) updateable views.
1. Required field (NOT NULL) in a joined table remains required in the view. My data access components read the meta information and throw error, when nothing (NULL) is put into that field. If something different than NULL is put though, the DB throws error because this is attempt to update multiple tables. That functionality may be disabled
in the data access components, resulting not that clean and easy to maintain exception
handling code.
2. CONSTRAINTS problem. It seems that any constraints on VIEW cannot be applied.
In the original table. I had UNIQUE field, and I placed UNIQUE DISABLED NOVALIDATE
in the view as constraint to that field in the view. It didn't prevent me to put several
rows with the same value in that field, which appeared in the original table.
It would be perfect if I could somehow manipulate the view meta information so my application can work with it as it was the original table (well, the original table with several read-only columns more). Is that possible in Oracle DB?

Answer 1

Hi.
For this part
"..the DB throws error because this is attempt to update multiple tables"
You may want to write an Instead-of-trigger
Regards
Peter