Calling Oracle function and Procedure using OCCI with in C++ code

Question

Could any body send me the sample code to create and execute Oracle function and Procedure using OCCI concept in C++?.
Edited by: 788634 on Aug 16, 2010 4:09 AM

Answer 1

Hi Vishnu,
Yes, sure, you can create a PL/SQL procedure, function, package, package body, etc. from within an OCCI application. I would say that, generally, this is not the sort of activity a typical client application would perform unless there is some initialization/installation processes that need to happen. In any case, here is a simple demo showing how to create a stand alone procedure (in a real application I would use a package and body) that returns a ref cursor. The ref cursor is just a simple select of two columns in the hr.countries sample table. Of course, there is no error handling, object orientation, etc. in this demo - I wanted to keep the code as short and as simple as possible to illustrate the concept.
Regards,
Mark
#include <occi.h>
#include <iostream>
using namespace std;
using namespace oracle::occi;
int main(void)
  // occi variables
  Environment *env;
  Connection  *con;
  Statement   *stmt;
  ResultSet   *rs;
  // database connection information
  string user = "hr";
  string passwd = "hr";
  string db = "orademo";
  // sql to create the procedure which returns a ref cursor as out parameter
  // should be run as hr sample user or in a schema that has select privilege
  // on the hr.countries table and a synonym (countries) that points to the
  // hr.countries table
  string sqlCreate =
    "create or replace procedure get_countries(p_rc out sys_refcursor) as "
    "begin"
    " open p_rc for"
    " select country_id, country_name from countries order by country_name; "
    "end;";
  // pl/sql anonymous block to call the procedure
  string sqlCall = "begin get_countries(:1); end;";
  // create a default environment for this demo
  env = Environment::createEnvironment(Environment::DEFAULT);
  cout << endl;
  // open the connection to the database
  con = env->createConnection(user, passwd, db);
  // display database version
  cout << con->getServerVersion() << endl << endl;
  // create statement object for creating procedure
  stmt = con->createStatement(sqlCreate);
  // create the procedure
  stmt->executeUpdate();
  // terminate the statement object
  con->terminateStatement(stmt);
  // now create new statement object to call procedure
  stmt = con->createStatement(sqlCall);
  // need to register the ref cursor output parameter
  stmt->registerOutParam(1, OCCICURSOR);
  // call the procedure through the anonymous block
  stmt->executeUpdate();
  // get the ref cursor as an occi resultset
  rs = stmt->getCursor(1);
  // loop through the result set
  // and write the values to the console
  while (rs->next())
    cout << rs->getString(1) << ": " << rs->getString(2) << endl;
  // close the result set after looping
  stmt->closeResultSet(rs);
  // terminate the statement object
  con->terminateStatement(stmt);
  // terminate the connection to the database
  env->terminateConnection(con);
  // terminate the environment
  Environment::terminateEnvironment(env);
  // use this as a prompt to keep the console window from
  // closing when run interactively from the IDE
  cout << endl << "ENTER to continue...";
  cin.get();
  return 0;
}