To pass new session variable value to stored proc before running a report.

Question

Hi,
Below is summary of the report requirement -
Database level design
1. Created a view and a global temporary table (GTT)
2. Created an Oracle package procedure to accept from and to business dates on basis of which it will fetch, process and populate the GTT.
Repository level design
1. Created a business model containing the view and the GTT (mentioned above)
2. Created two SESSION variables "from_dt" and "to_dt" to be initialized by their respective init blocks. Each of the variable is initialized with a DATE column value (of type DATETIME) from a database lookup table. I have also set the option "Enable that variable to be set by any user" for both variables.
Query for these variables :
from_dt = select from_date from <table>
to_dt = select add_months(from_date,12) from <table>
Presentation level design
1. Using a text box, i display the default/initialized values of these variables like this -
Current business date:@{biServer.variables['NQ_SESSION.from_dt']} Future business dt:@{biServer.variables['NQ_SESSION.to_dt']}
Dates get displayed in YYYY-MM-DD 00:00:00 format
The text msg displays these default dates and allows the user to specift different date range for which i create prompts as shown below.
2. Using any random two columns of date type from the business model, i create two date dashboard prompts with labels "From Dt" and "To Dt".
i select Calender Controls for both; setting Default To = Report Defaults.
The Set Variable is set to Presentation variables - such that pv_from_dt maps to "From Dt" and pv_to_dt maps to "To Dt".
3. i create the report using the business model created above. In the report "Advanced Tab" => "Prefix" field i specify the following -
SET VARIABLE from_dt='@{pv_from_dt}',to_dt='@{pv_to_dt}';
Note : The logic here is to display the default dates and allow user to specify different date values which will be stored in presentation variables.
If the user does specify different "from dt" and "to dt" values, then using the presentation variables, i want to "write" back these new values to the corresponding session variables mentioned above.
If the user does not specify different date range, then the default/initialized dates must be considered.
I also display the default and new date values in the report title.
Back to Repository level design
To execute the stored procedure that will load the GTT before running the report I need to pass two date parameters to the stored procedure on basis of which it will fetch data, process and populate the GTT.
In the Connection Pool --> Connection Script Tab --> Execute before query, I wrote the below query using the repository variables FROM_DT and TO_DT to execute the procedure -
DECLARE
v_from_dt date;
v_to_dt date;
BEGIN
v_from_dt := VALUEOF(From_Dt);
v_to_dt := VALUEOF(To_Dt);
package_name1.package_body(v_from_dt,v_to_dt);
END;
Now when i try to run the report i get the following error :
[nQSError: 10058] A general error has occurred. [nQSError: 23006] The session variable, NQ_SESSION.to_dt, has no value definition. (HY000)..
Need help on this.
Is it possible to "write back" a new value to a session variable ?
Any other alternatives.
Thanks
Nusrat
Edited by: user10309945 on Jan 24, 2011 10:08 PM

Answer 1

Sandeep, I found a several topics where users describe saving values in DB through stored procedure or function. For example, [How to store OBIEE presentation level variable values in DB |http://forums.oracle.com/forums/thread.jspa?threadID=892006] I tried it and get an error
*10058. [NQODBC] [SQL_STATE: HY000] [nQSError: 10058] A general error has occurred. [nQSError: 17001] Oracle Error code: 14551, message: ORA-14551: cannot perform a DML operation inside a query ORA-06512*
It's not a BI error. This error are generated by Oracle DB. If I write next:
SELECT MyPLSQLFunction(p1,p2) FROM DUAL
I get the same error.
Oracle doesn't allow DML operations in SELECT.
Did you relalize this feature yourself? Where did I mistake?