Re: C code problem - Mailing list pgsql-novice

Thanks for the code.  It works great.

It looks like there is a definite difference between the way that PQsetdb and
PQconnectdb "open" the database connection.  Until now I've been using
PQconnectdb with no problems.

"D. Duccini" wrote:

> here's some code i wrote for generically dealing with postgres in C
>
> --> modify the 'connect' as you see fit -- mine was based on SUID user
> processing for some daemons we were using
>
> void SQLShutdown(PGconn *conn)
> {
>    PQfinish(conn);
> }
>
> int SQLString(char *is, char *os)
> {
>    char  *ch=is,
>          *ch2=os;
>
>    while (*ch) {
>       if (*ch == '\'')
>          *ch2++ = '\'';
>       *ch2++ = *ch++;
>    }
>    *ch2 = 0;
>    return(0);
> }
>
> PGconn *SQLConnect(void)
> {
> PGconn   *conn;
>    char  *dbName = "",
>          *pghost = NULL,      /* host name of the backend server */
>          *pgport = NULL,      /* port of the backend server */
>          *pgoptions = NULL,   /* special options to start up the backend
> server
> */
>          *pgtty = NULL;       /* debugging tty for the backend server */
>
>    Debugf("SQLConnect()\n");
>
>    conn = PQsetdb(pghost, pgport, pgoptions, pgtty, dbName);
>    if (PQstatus(conn) == CONNECTION_BAD) {
>       printf("Connection to database '%s' failed.\n", dbName);
>       printf("%s",PQerrorMessage(conn));
>       return(NULL);
>    }
>    return(conn);
> }
>
> int SQLDisconnect(PGconn *conn)
> {
>    PQfinish(conn);
> }
>
> PGresult *SQLExecute(PGconn *conn, char *xBuf, int resultOK)
> {
>    PGresult *res;
>
>    printf("%s\n", xBuf);
>
>    res = PQexec(conn, xBuf);
>    if (PQresultStatus(res) != resultOK) {
>       printf("PQresultStatus(res) : %d\n", PQresultStatus(res));
>       printf("! Command failed\n");
>       PQclear(res);
>       return(NULL);
>    }
>    else
>       return(res);
> }
>
> PGresult *SQLExecuteQuietly(PGconn *conn, char *xBuf, int resultOK)
> {
>    PGresult *res;
>
>    res = PQexec(conn, xBuf);
>    if (PQresultStatus(res) != resultOK) {
>       printf("PQresultStatus(res) : %d\n", PQresultStatus(res));
>       printf("! Command failed\n");
>       PQclear(res);
>       return(NULL);
>    }
>    else
>       return(res);
> }
>
> -duck
>
> On Tue, 17 Apr 2001, John Burski wrote:
>
> > I'm running PostgreSQL 7.0.3 on a Red Hat 6.1 box and am having a bit of
> > trouble with some C code.
> >
> > I'm able to connect to the database OK (host = localhost, hostaddr =
> > 127.0.0.1, dbname = template1, user = postgres (the superuser), password
> > = whatever), but a PGRES_NONFATAL_ERROR status results from the
> > following query:
> >
> >      result = PQexec ( dbc, "SELECT * FROM pg_user" );
> >
> > If I run the query from an interactive session it works fine.  I've
> > other programs that work fine, but none of them connect to "template1"
> > or attempt to access the system tables.  Is there some sort of access
> > restriction related to the system tables?
> >
> > Thanks.
> >
> > --
> > John Burski
> > I.T. Manager
> > 911 Emergency Products
> > 25 Sixth Avenue North
> > St. Cloud, MN  56303
> > (320) 656 0076       www.911ep.com
> >
> > ++++++++++++++++++++++++++++++++++
> > + How's your cheese holding out? +
> > ++++++++++++++++++++++++++++++++++
> >
> >
> >
> >
> > ---------------------------(end of broadcast)---------------------------
> > TIP 4: Don't 'kill -9' the postmaster
> >
>
> -----------------------------------------------------------------------------
> david@backpack.com            BackPack Software, Inc.        www.backpack.com
> +1 651.645.7550 voice       "Life is an Adventure.
> +1 651.645.9798 fax            Don't forget your BackPack!"
> -----------------------------------------------------------------------------

--
John Burski
I.T. Manager
911 Emergency Products
25 Sixth Avenue North
St. Cloud, MN  56303
(320) 656 0076       www.911ep.com

++++++++++++++++++++++++++++++++++
+ How's your cheese holding out? +
++++++++++++++++++++++++++++++++++