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Re: help !!!

From: "Goulet, Dick" <DGoulet(at)vicr(dot)com>
To: "apellido jr(dot), wilfredo p(dot)" <apellido(at)mactan(dot)ph>,<pgsql-interfaces(at)postgresql(dot)org>
Subject: Re: help !!!
Date: 2004-06-30 14:11:11
Message-ID: 4001DEAF7DF9BD498B58B45051FBEA650146C47A@25exch1.vicorpower.vicr.com (view raw or flat)
Thread:
Lists: pgsql-interfaces
PGgetValue returns a character pointer, so if you have:

	char *reply_string = NULL;

	reply_string = PQgetResult(rex,0,0);
	

Dick Goulet
Senior Oracle DBA
Oracle Certified 8i DBA

-----Original Message-----
From: apellido jr., wilfredo p. [mailto:apellido(at)mactan(dot)ph]
Sent: Wednesday, June 30, 2004 9:26 AM
To: pgsql-interfaces(at)postgresql(dot)org
Subject: [INTERFACES] help !!!


Hello! im a newbie in C programing as well as Postgresql. The above example
is workin but im having difficulty regarding assigning the result of Query
Select.  here's the program

        int
        main()
        {
            char        UserName[50];                          /* holds user
state code */
            char        query_string[256];                      /* holds
constructed SQL query */
            PGconn     *conn;                                   /* holds
database connection */
            PGresult   *res;                                    /* holds
query result */

            conn = PQconnectdb("dbname=grade");                  /* connect
to the database */

            if (PQstatus(conn) == CONNECTION_BAD)               /* did the
connection fail? */
            {
                fprintf(stderr, "Connection to database failed.\n");
                fprintf(stderr, "%s", PQerrorMessage(conn));
                exit(1);
            }

            printf("Enter Username:  ");                    /* prompt user
for a state code */
            scanf("%s", UserName);

            sprintf(query_string,                               /* create an
SQL query string */
                    "SELECT username, value
                     FROM table1
                     where test = 'grade' and username = '%s'", UserName);

            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);
            }

            printf("\n\n\n");
            printf("Username :  %s\n\n\n", PQgetvalue(res, 0, 0));
            printf("Grade : %s  \n\n\n", PQgetvalue(res, 0, 1));

            PQclear(res);                                       /* free
result */

            PQfinish(conn);                                     /*
disconnect from the database */

            return 0;
        }

############################################################################
########


hello how can i assign to certain variable the output of PQgetvalue(res, 0,
1)? example i want to do like this ...

a = PQgetvalue(res, 0, 1)
printf("Grade : %s  \n\n\n", a );

and then after assigning the value of PQgetvalue(res, 0, 1) to a then ...

b = a \ 2;

but  it is possible to divide the output of "a" where it is a var and "b" is
integer?












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