Ever used the Designer Table API (TAPI) with object type in the DB?

Question

Hi all,
We are trying to generate the Oracle Designer table API of a table that has a column defined by an object type. It works without problems if that column always has a value (is instantiated in object term). The problem is when we update a row where the column is null (all attributes of the object are null thus the object is not instantiated).
The "before update row" trigger of the Table API fails with error "ora-30625-method dispath on NULL SELF argument is disallowed".
The code that fails is the following:
cg$ind.TFO_DESCRIPTION :=(:new.TFO_DESCRIPTION IS NULL AND :old.TFO_DESCRIPTION IS NOT NULL )
OR (:new.TFO_DESCRIPTION IS NOT NULL AND :old.TFO_DESCRIPTION IS NULL)
OR NOT(:new.TFO_DESCRIPTION = :old.TFO_DESCRIPTION) ;
In this example, cg$ind.TFO_DESCRIPTION is a boolean and the TFO_DESCRIPTION column is based on an object type.
Thanks for any feedback or suggestions

Answer 1

For a solution to this problem: I set down to write a relatively simple and small piece of code that we can use as post compiler or post generator. After we generated one or more TAPIs, we can run this post compiler to remedy the problem the TAPI has with Merge operations. The post compiler will fix the PL/SQL inside the database. It reads the TAPI objects using dbms_metadata, makes the simple change by manipulating the PL/SQL source and then recreates the objects using execute immediate. Using this post compiler, it takes but a few seconds to fix the merge flaw in all TAPIs in your application.
http://technology.amis.nl/blog/index.php?p=842