Change objects in database

Question

Hallo,
I've an oracle sqlj type, which implements the SQLData interface. To use it in a Java application, I use an other implementation of SQLData, which calls the methods of my oracle object via JDBC. So the functionallity is done in database.
In my java application, I get the database objects with queries like this and bind the results to my java class.
   SELECT objectX
   FROM tableX
   WHERE id = x;Now I want to call member procedures of my object type (which eventually are executed in database). These procedures change some of the attributes of my oracle type. According to the documentation, it is necessary to call an update statement in the server implementation, to write these changes to the database. The code could look something like this:
   PreparedStatement pstmt = conn.prepareStatement
    ("UPDATE tableX     SET objectX = ?    WHERE ID = x");
   pstmt.setObject(1, obj);   // obj is java representation of objectX
   pstmt.executeUpdate();So far it works fine. The problem is, that my oracle object itself must know about the query, it originates from. Is there any way, to update the changed object in database without this knowledge?
My ultimativ goal is a member procedure in the server implementation like this:
    void writeObject() {
       PreparedStatement pstmt = conn.prepareStatement
       ("UPDATE ?");
       pstmt.setObject(1, this);
       pstmt.executeUpdate();
    }I hope, my problem is clear and you have any ideas for me.
Thanks, Christian

Answer 1

Christian,
Are you aware of the JPublisher utility? Once you have types defined in the database, JPub can generate Java classes that map to the defined types. To learn more, check out the online doc at http://download-west.oracle.com/docs/cd/B10501_01/java.920/a96658/toc.htm.
There are many examples in the doc to give you better picture of how it works.
Regards,
Geoff