How describe model data and get select in DB throw topLink.

Question

Hello,
I have table from code
create table t_tree
id int primary key,
parent_id int,
value varchar2(255)
Alter table t_tree
add constraint constr_id_parent foreign key (parent_id) references t_tree (id)
I must get query
select level as lv,lpad('-@-', (level-1)*2)||value as MMM, t.* from t_tree t
connect by prior id=parent_id
start with T.PARENT_ID is null
How describe model data and get select in DB throw topLink.
Dema.

Answer 1

So you'll probably have to write a function which uses dynamic SQL to retrieve the desired message text, like this untested one:
CREATE OR REPLACE FUNCTION get_msg(p_db IN VARCHAR2,
                                   p_id IN NUMBER)
   RETURN VARCHAR2
IS
   msg_txt  VARCHAR2(4000);
BEGIN
   -- make sure p_db is a valid database link ...
   EXECUTE IMMEDIATE 'SELECT d_msg FROM msg@' || p_db || ' WHERE t_id = :id' INTO msg_txt USING p_id;
   RETURN msg_txt;
EXCEPTION
   WHEN NO_DATA_FOUND THEN
      RETURN NULL;
END get_msg;
/The you can update likeUPDATE mex
   SET t_msg = get_msg(db_id, t_id);Hth, Urs