PostgresSQL server connectiong problem with C-language...

[madhu542]

I wrote C-program for connecting to postgresSQL server and get the data from the database.

The program is as fallows:-

#include <stdio.h>
#include <stdlib.h>
#include "libpq-fe.h"                                   /* libpq header file */
int
main()
{
    char        state_code[3];                         
    char        query_string[256];                      /* holds constructed SQL query */
    PGconn     *conn;                                   /* holds database connection */
    PGresult   *res;                                    
    int         i;
    conn = PQconnectdb("dbname=test");                  /* connect to the database */
    if (PQstatus(conn) == CONNECTION_BAD)               /* did the database connection fail? */
    {
        fprintf(stderr, "Connection to database failed.\n");
        fprintf(stderr, "%s", PQerrorMessage(conn));
        exit(1);
    }
    printf("Enter a state code: ");                     /* prompt user for a state code */
    scanf("%2s", state_code);
    sprintf(query_string,                               /* create an SQL query string */
            "SELECT name \
             FROM statename \
             WHERE code = ’%s’", state_code);
    res = PQexec(conn, query_string);                   /* send the query */
    if (PQresultStatus(res) != PGRES_TUPLES_OK)         /* did the query fail? */
    {
        fprintf(stderr, "SELECT query failed.\n");
        PQclear(res);
        PQfinish(conn);
        exit(1);
    }
    for (i = 0; i < PQntuples(res); i++)                /* loop through all rows returned */
        printf("%s\n", PQgetvalue(res, i, 0));          /* print the value returned */
    PQclear(res);                                       /* free result */
    PQfinish(conn);                                     /* disconnect from the database */
    return 0;
}
 

every time I a getting the same error:-

Connection to database failed.
could not connect to server: No such file or directory
Is the server running locally and accepting
connections on Unix domain socket "/var/run/postgresql/.s.PGSQL.5432"?

could any plz help me how to solve this problem...

Thanks & Regards...

[weaknessforcats]

Please use code tags.

I added them for you this time.

[madhu542]

Please use code tags.

I added them for you this time.

I tried with ur code ... but I am still getting the same error...

even I changed the posgresql.conf and pg_hda.conf. and tried same result.

Thanks & Regards...

[Meetee]

I tried with ur code ... but I am still getting the same error...

even I changed the posgresql.conf and pg_hda.conf. and tried same result.

Thanks & Regards...

Moderator has not given new code. He has just put code tags which will make your code and post clearly readable. In Reply Guidelines, it is mentined that when you post any code "Use CODE tags around your code:[ CODE ]..code goes here..[ /CODE ]" So your code is not changed anyway by him :)

Regards