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 |
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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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