Error on a Dynamic Select using Pro*C

Question

I am a new user on Pro*C and I am facing an error for which I could not find a solution in the Pro*C/C++ Programmer’s Guide. The problem occurs when I do a dynamic SELECT to retrieve sequence of numbers (from 0 to 10) from a very simple table in a database.
The program is retrieving the following sequence: {705, 961, 1217, 1473, 1729, 1985, 2241, 2497, 2753, 3009} rather than the sequence {1, 2, 3, 4, 5, 6, 7, 8, 9, 10}.
It’s very interesting to notice that the retrieved sequence, in hexadecimal, is equal to {2C1, 3C1, 4C1, 5C1, 6C1, 7C1, 8C1, 9C1, AC1, BC1}.
I am quite sure that I'm missing a small detailed here and I would appreciate
any help. Please find below the code that I am using.
Thanks a lot!
#include <string>
#include <iostream>
using namespace std;
#include <sqlca.h>
#include <sqlcpr.h>
EXEC SQL BEGIN DECLARE SECTION;
VARCHAR username[30];
VARCHAR password[30];
VARCHAR db_name [30];
VARCHAR dns_name[30];
EXEC SQL END DECLARE SECTION;
void SQL_Error ( void )
char msg[200];
size_t buf_len = sizeof ( msg );
size_t msg_len;
sqlglm( msg, &buf_len, &msg_len );
if ( msg_len > buf_len )
msg_len = buf_len;
cout << msg << endl;
bool OpenDBConnection( char uname, char pword, char dns, char dbname )
// Assign the database identifications to the ORACLE variables
username.len = (unsigned short) strlen ( strcpy( (char *) username.arr, uname ) );
password.len = (unsigned short) strlen ( strcpy( (char *) password.arr, pword ) );
dns_name.len = (unsigned short) strlen ( strcpy( (char *) dns_name.arr, dns ) );
db_name.len = (unsigned short) strlen ( strcpy( (char *) db_name.arr , dbname ) );
/* Register sql_error() as the error handler */
EXEC SQL WHENEVER SQLERROR goto err;
/* Connect to the non default database */
EXEC SQL CONNECT :username IDENTIFIED BY :password AT :db_name USING :dns_name;
return ( true );
err:
SQL_Error();
return ( false );
** Select the database using a dynamic method
long SelectIDRecord ( void )
EXEC SQL BEGIN DECLARE SECTION;
// Define the dynamic statement
char dyn_statement[4000];
// Define the bind variables
long db_id = 0;
long db_id_type = 2; /* NUMBER */
long db_id_len = 10;
EXEC SQL END DECLARE SECTION;
// Initialize the dynamic statement
memset ( dyn_statement, 0, sizeof( dyn_statement ) );
strcpy ( dyn_statement, "SELECT ID FROM TEST_DB ORDER BY ID" );
EXEC SQL AT :db_name PREPARE s1 FROM :dyn_statement;
// Declare and initialize the output descriptor
EXEC SQL ALLOCATE DESCRIPTOR 'out';
EXEC SQL AT :db_name DESCRIBE OUTPUT s1 USING DESCRIPTOR 'out';
EXEC SQL SET DESCRIPTOR 'out' value 1 TYPE = :db_id_type,
LENGTH = :db_id_len, DATA = :db_id;
// Declare and open the cursor
EXEC SQL AT :db_name DECLARE test_db_cursor CURSOR FOR s1;
EXEC SQL AT :db_name OPEN test_db_cursor;
EXEC SQL WHENEVER NOT FOUND DO BREAK;
long nRec = 0;
while ( true )
EXEC SQL AT :db_name FETCH test_db_cursor INTO DESCRIPTOR 'out';
EXEC SQL GET DESCRIPTOR 'out' VALUE 1 :db_id = DATA;
nRec++;
cout << "ID = " << (long) db_id << endl;
// Close the cursor
EXEC SQL AT :db_name CLOSE test_db_cursor;
EXEC SQL DEALLOCATE DESCRIPTOR 'out';
return ( nRec );
err:
SQL_Error();
return ( 0 );
int main ()
char *uname  = "test";
char *pword  = "test";
char *dns    = "test_db";
char *dbname = "test";
OpenDBConnection ( uname, pword, dns, dbname );
long nRec = SelectIDRecord ();
}

Answer 1

No need to specify the length if the data type is number and pointing to Long.
You can directly map the values using INTO clause.