[Dev-C++] PostgreSQL and Dev-Cpp Dev-C++ on Windows example

[Reid T. <jre...@ea...>]

I thought it might be of interest to post steps to using PostgreSQL on 
Windows with the Dev-Cpp/MINGW IDE/compiler.  This example is C, but the 
steps for configuring the IDE/Project to use the PostgreSQL libs/headers 
should be the same or very similar for C++/ecpg.

Install PostgreSQL for Windows using the windows installer ( for those 
who haven't used the PostgreSQL windows installer, it's a quick and easy 
process ).

Start Dev-C++.
File->New->Project.
Select Console Application.
Select C project.
Give the project a pertinent name ( myPgsqlTest ).
Click OK.
Create a new dir to contain the Project ( give it a pertinent name).
Save the initial project.
Select Project->Project Options.
  Select the Parameters Tab.
  Click the Add Library or Object button.
    Traverse to your PostgreSQL installation's lib directory - mine is
    ../../../PostgreSQL/8.0/lib/ and select libpq.a.
    In my case, the linker window now contains 
../../../PostgreSQL/8.0/lib/libpq.a.
  Select the Directories Tab.
    Select the Include Directories sub-tab.
      Traverse to and select your PostgreSQL installation's include 
directory - mine is
      D:\PostgreSQL\8.0\include.
      Click on Add ( your Include directories window should now list 
this path.
Click on OK to close the Project Options Dialog

Insure that the db 'test' exists in your PostgreSQL instance, or change 
'test' in the conninfo to your test db when you populate the other 
appropriate values for your connection. 

Replace the Dev-C++ template created main.c

#include <stdio.h>
#include <stdlib.h>

int main(int argc, char *argv[])
{
 
  system("PAUSE");   
  return 0;
}

with ( this is based on the libpq example from www.postgresql.org/docs )

#include <stdio.h>
#include <stdlib.h>
#include <time.h>
#include "libpq-fe.h"

static void
exit_nicely(PGconn * conn)
{
    PQfinish(conn);
   
    
/***************************************************************************
    * I added this because it's the 'default' means of preventing the 
cmd.exe
    * window from closing in Dev-C++.  Note that this is only needed when
    * running the resultant executable from within Dev-Cpp itself or via
    * clicking on the file with the mouse pointer
    
***************************************************************************/
    system("PAUSE");
   
    exit(1);
}

int
main(int argc, char **argv)
{
    time_t t1;
    time_t t2;
    /* mingw time.h doesn't have struct timeval
    struct timeval tb1;
    struct timeval tb2;
    */
    const char *conninfo;
    PGconn *conn;
    PGresult *res;
    int i, j = 0;
    long t_diff = 0;
    char statement[1024];
    char buffer[50];

    /*
     * If the user supplies a parameter on the command line, use it as
     * the conninfo string; otherwise default to setting dbname=template1
     * and using environment variables or defaults for all other connection
     * parameters.
     */
    if (argc > 1)
    {
        conninfo = argv[1];
    }
    else
    {
        conninfo = "hostaddr = 127.0.0.1 dbname = test user = postgres 
password = postgres";
    }

    /* Make a connection to the database */
    conn = PQconnectdb(conninfo);

    /* Check to see that the backend connection was successfully made */
    if (PQstatus(conn) != CONNECTION_OK)
    {
        fprintf(stderr, "Connection to database failed: %s",
                PQerrorMessage(conn));
        exit_nicely(conn);
    }

    res = PQexec(conn, "drop table notes");
    if (PQresultStatus(res) != PGRES_COMMAND_OK)
    {
        fprintf(stderr, "drop table command failed: %s", 
PQerrorMessage(conn));
         PQclear(res);
        /* exit_nicely(conn);
        * commented out so that we don't have to create the
        * table manually before we run
        */
    }
    PQclear(res);

    res = PQexec(conn, "create table notes(subject text)");
    if (PQresultStatus(res) != PGRES_COMMAND_OK)
    {
        fprintf(stderr, "create table command failed: %s", 
PQerrorMessage(conn));
        PQclear(res);
        exit_nicely(conn);
    }
    PQclear(res);

    res = PQexec(conn, "BEGIN");
    if (PQresultStatus(res) != PGRES_COMMAND_OK)
    {
        fprintf(stderr, "BEGIN command failed: %s", PQerrorMessage(conn));
        PQclear(res);
        exit_nicely(conn);
    }
    PQclear(res);

    (void) time(&t1);
    /* (void) gettimeofday (&tb1, NULL); */
    for (i = 1; i < 2001; i++)
    {
        sprintf(buffer, "my subject%d", i);

        sprintf(statement, "%s %s%s", "insert into notes(subject) values('",
                buffer, "')");
               
        res = PQexec(conn, statement);
        if (PQresultStatus(res) != PGRES_COMMAND_OK)
        {
            fprintf(stderr, "insert command failed: %s", 
PQerrorMessage(conn));
            PQclear(res);
            exit_nicely(conn);
        }
        PQclear(res);
    }
    res = PQexec(conn, "COMMIT");
    PQclear(res);
   
    (void) time(&t2);
    /* (void) gettimeofday (&tb2, NULL); */

    printf("added %d records to notes\n", i - 1);
    printf("time1: %d time2: %d\n", t1, t2);
    printf("elapsed time: %d\n", (t2 - t1));
    printf("The start time was %s.\n", asctime(localtime(&t1)));
    printf("The end time was %s.\n", asctime(localtime(&t2)));
    /*
     * t_diff = (long) ((tb2.tv_sec - tb1.tv_sec) + (tb2.tv_usec -
     * tb1.tv_usec)); printf ("seconds: %ld end_microsecs: %ld 
start_microsecs
     * %ld microsecs %ld\n", (tb2.tv_sec - tb1.tv_sec), tb2.tv_usec,
     * tb1.tv_usec, tb2.tv_usec - tb1.tv_usec); t_diff = (long) (1000.0 *
     * (tb2.tv_sec - tb1.tv_sec) + (tb2.tv_usec - tb1.tv_usec)); 
printf("elapsed
     * time millisecs: %ld\n", t_diff); */

    /* close the connection to the database and cleanup */
    PQfinish(conn);

    
/***************************************************************************
    * I added this because it's the 'default' means of preventing the 
cmd.exe
    * window from closing in Dev-C++.  Note that this is only needed when
    * running the resultant executable from within Dev-Cpp itself or via
    * clicking on the file with the mouse pointer
    
***************************************************************************/
    system("PAUSE");

    return 0;
}