Organization: ESAT, K.U.Leuven, Belgium
From: Joris Esch <joris.esch@esat.kuleuven.ac.be>
Reply-To: joris.esch@esat.kuleuven.ac.be
To: "Vasquez, Jason" <Jason.Vasquez@Connect.Xerox.com>
Subject: Re: [INTERFACES] PgConnection
Date: Thu, 22 Oct 1998 09:33:02 +0200
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Cc: pgsql-interfaces@hub.org
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On Wed, 21 Oct 1998, you wrote:
>I have just installed PostgreSQL, and the installation took place with no
>problems/errors.
>
>I've read the documentation about using the C++ interface to Postgres, but I
>seem to be havin trouble getting anything to compile.  Following the example
>included with the distribution, I have done something similar to this:
>
>#include <iostream.h>
>#include <libpq++.h>
>
>void main() {
>  PgDatabase data ("foo");
>
>yadayadayada
>}
>
>Whenever I do this, I get a compile error stating that there is an undefined
>reference to PgConnection.  Has anyone had a similar situation, or know how
>to remedy this?
>
>Thanks,
>-Jason

Hello:

look at the attached code. I hope it's usefull for you.

good luck
joris

--
joris esch, student in electrical engineering
		Power is knowledge.
	

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/* test3.cpp
joris esch 3.10.1998
*/
// compile with:
// c++ test3.cpp -o test3 -lpq -lpq++

#include "test3.h"

void main()
{
          
  bool verbose = true;
  char* dbname= "template1";        
 

  /* make a connection to the database */
 
  if (verbose) {
    cout << "Trying to connect to db " << dbname  << '\n';;  // << " on host " << pghost;
  } ;
  
  // PgDatabase inherits from PgConnection
  PgDatabase *conn=new PgDatabase(dbname);

  // give error messages if conn is not ok

  if (conn->Status()!=0){
    cerr << "Connection status: " << conn->Status() <<'\n';
    cerr << "Connection failed." << '\n';
    cerr << "Database name: " << conn->DBName() << '\n';
    cerr << conn->ErrorMessage() << '\n';
    //end execution here... or use exception handling...cfr. ch8
    exit(1); //Stroustrup page 116 0== okidoki, 1!=okidoki
    //throw "Connection failed";
  }; 
  
  if (verbose) {cout <<  "Connection succeeded.\n";};
  cout << "You are currently connected to db: " << conn->DBName() << '\n';
  //cout << "Let's do a query";
  //see if i can do  query...
  if (conn->ExecTuplesOk("DECLARE mycursor BINARY CURSOR FOR select * from pg_database")){// 1 means Ok
    int no_t=conn->Tuples();
    int no_f=conn->Fields();
    if (verbose) {
      cout << "The number of tuples in the query: " << conn->Tuples() << '\n';
      cout << "The number of fields in the query: " << conn->Fields() << '\n';
    }
    cout << "The query results: \n";
  
    for(int i=0;i < no_t; i++){
      for(int j=0;j < no_f; j++){
	cout << conn->GetValue(i,j) << '\t';
	//cout << conn->GetValue(i,j) << '\n';
      }
      cout << '\n';
    }
  } else{
    cout << "Execution of query failed\n";//conn
  }

  //conn->Exec("DECLARE mycursor BINARY CURSOR FOR select * from test");
  
  //return 0;
  
}

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/* test3.h
joris esch 3.10.1998
*/

#include <libpq++.h>

#include <iostream>
 
//typedef int Error;

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