Create a cursor from a PL/SQL variable or an external file

Question

Dear friends,
is there a way for me to make Oracle Forms read a cursor from a PL/SQL variable, or an external file? Let's suppose we have the code below:
DECLARE
cursor c_values is select * from my_table;
r_values c_values%ROWTYPE;
BEGIN
for r_values in c_values loop
do_something;
end loop;
END;
In the situation described above, could I create "select * from my_table" from a PL/SQL variable (it could be something like p_cursor = 'select * from my_table'), or an external file - for example, make my form read the contents of c:\my_select.sql , where we see the "select * from my table" text?
My question comes because I need to export data from select instructions that were dinamically created inside the form - that is, via PL/SQL -, and I don't want to rewrite it, but I'll have to do it if I have no choice. Your help will be greatly appreciated.
Best regards,
Franklin
Edited by: franklinbrasil on 12/03/2009 11:33
Edited by: franklinbrasil on 12/03/2009 11:35

Answer 1

Dear friends,
I am using DBMS_SQL package, which solved my problem. Please let me explain it better, if it's not clear.
I have some PL/SQL blocks inside my form, which creates SQL queries dinamically, and a dinamically created SQL is stored into a VARCHAR2 variable. These SQL queries are exported for use in Oracle Graphics, but since OG is not being developed by Oracle anymore then I am trying to find a substitute for it.
So I thought about creating an option for the final user: he/she can choose exporting data into Microsoft Excel, and user does what he/she wants, creating a customized graphic. Exporting into Excel works finely, with no problems at all - I could find a routine by searching on the web.
My goal was to use the same queries created above to export data dinamically to Microsoft Excel, and I absolutely don't want to rewrite all these dinamically created queries - one which works dinamically, other with no flexibility inside my form. Worse than it, I have many other dinamically created queries, and I obviously don't want to rewrite them all - any maintenance in this form would be terrible, with each SQL instruction written twice.
Since all dinamically created SQL instructions are stored inside a VARCHAR2 variable, I thought about reusing the same SQL, as explained above - and here we have your suggestions about using a ref cursor, execute immediate, and so on. And (answering Andreas) query structure is always based on the same table, but its structure changes a lot, depending on what the final user chooses in a drop-down list (it's a list of graphics options, where final user chooses one option, and form must mount SQL dinamically, based on user's choice).
By using your explanations, I could find DBMS_SQL solution here: http://download.oracle.com/docs/cd/B10501_01/appdev.920/a96590/adg09dyn.htm#26799
. Please notice that I had to change DBMS_SQL.native into 1 for it to work in my form. I'll mark all your answers as helpful because I can use them both for database and form purposes.
If my message was not clear enough, please tell me and I'll try to make it more clear.
Best regards,
Franklin