Communicating with PostgreSQL Using LibPQ - PostgreSQL Developer's Guide - page 172

fprintf(stderr, "%s", PQerrorMessage(conn));
return -1;
}
fprintf(stdout, "Connection to database established using
PQconnectdb\n");
PQfinish(conn);
/* Connect database using PQconnectdbParams */
conn = PQconnectdbParams((const char **)keyword, (const char
**)value, 1);
if (PQstatus(conn) == CONNECTION_BAD)
{
fprintf(stderr, "connection to database failed using
PQconnectdbParams\n");
fprintf(stderr, "%s", PQerrorMessage(conn));
return -1;
}
fprintf(stdout, "Connection to database established using
PQconnectdbParams\n");
PQfinish(conn);
/* Connect database using PQsetdbLogin */
conn = PQsetdbLogin("127.0.0.1", "5432", NULL, NULL, "testdb",
"foo", "bar");
if (PQstatus(conn) == CONNECTION_BAD)
{
fprintf(stderr, "connection to database failed using
PQsetdbLogin\n");
fprintf(stderr, "%s", PQerrorMessage(conn));
return -1;
}
fprintf(stdout, "Connection to database established using
PQsetdbLogin\n");
PQfinish(conn);
return 0;
}