Cursor Variables in Pro*C/C++

Question

I have very strange behaivour of the client application that uses cursor variable.
I have Oracle 8i enterprise 8.1.6 release for Sun/Solaris.
The follow SQL is installed on server:
create or replace package dummy is
type vemap_cur is ref cursor;
end;
create or replace procedure GET_CUR
( N IN number, cur IN OUT dummy.VEMAP_CUR ) as
begin
open cur for
select LS.ID, LS.SCALE
from LAYERS LS
where LS.ID = (select C.ID from CTM C where C.ORDERINDEX = N);
end;
This procedure (GET_CUR) i call from embedded SQL in follow manner:
EXEC SQL BEGIN DECLARE SECTION;
struct
int n1;
int n2;
} resrec;
sql_cursor c1;
int num;
EXEC SQL END DECLARE SECTION;
EXEC SQL ALLOCATE :c1;
EXEC SQL AT DB_VE EXECUTE
BEGIN
GET_VEC( :num, :c1 );
END;
END-EXEC;
Till now it is Ok. But when i run the follow line
EXEC SQL FETCH :c1 INTO :resrec;
i accept ORA-01012: not logged on
error !!!!
I checked the connection via using cursor in paralell and got the correct answer.
Therefore i think this error is not related to the actual problem and i have no idea what this problem is. I tried to open cursor via anonymous PL/SQL block inside my C program with same result.
Need help ASAP.
Leonid
null

Answer 1

Hi Leonid, Andrea
When you use "CONNECT AT :db_handle" instead of default connection "CONNECT", you have to give the connect handle to the command you want to execute.
ie:
EXEC SQL AT :db_handle PREPARE SQL_stat FROM "select ...";
EXEC SQL AT :db_handle DECLARE cur_stat CURSOR for SQL_stat;
EXEC SQL AT :db_handle OPEN cur_stat ;
EXEC SQL AT :db_handle FETCH cur_stat INTO :resrec;
Leonid, the error you had is probably because you connected at "DB_VE", and tried to select from default connect (that you're not connected to ==> ORA-01012)
Try EXEC SQL AT :DB_VE FETCH :c1 INTO :resrec;
or, if you connect to only 1 database, use "EXEC SQL CONNECT;" instead of (EXEC SQL CONNECT :pConnectString AT "DB_VE";) so that you use default connect name and you don't have to add "AT :DB_VE" to your SQL commands.
I know this reply comes long after your request, but I hope it may still help anybody.