Newbie: How to select into a char pointer in Pro*C?

Question

All Pro*C samples I have seen selects a VARCHAR2 column into a host char array. I want to used a char * instead. However, each time I run the program after successful Pro*C and C compilation, I get a critical error. Can someone share some working code using char * rather than char []? Thanks very much.

Answer 1

Did you actually allocate space for the data?Funny you mentioned it. Coming from a VB and Java background without C it was not obvious to me that I have to allocate memory after declaring a pointer. But I later found it is necessary. However, even with that I am getting an error. My code (copied from ora-faq and then modified) is like:
#include <stdio.h>
#include <sqlca.h>
void sqlerror();
EXEC SQL BEGIN DECLARE SECTION;
char *connstr = "scott/tiger";
char *db_ename;
int db_deptno;
EXEC SQL END DECLARE SECTION;
int main() {
db_ename = (char *) malloc(30);
EXEC SQL WHENEVER SQLERROR DO sqlerror();
     EXEC SQL WHENEVER SQLWARNING CONTINUE;
     EXEC SQL CONNECT :connstr;
     EXEC SQL WHENEVER NOTFOUND GOTO notfound;
     EXEC SQL SELECT ENAME, DEPTNO
          INTO :db_ename, :db_deptno
     FROM EMP
          WHERE EMPNO = 7369;
found:
     printf("%s is in department %i\n", *db_ename, db_deptno);
     return;
notfound:
     printf("Employee record not found in database.\n");
     return;
void sqlerror() {
     printf("Stop Error:\t%25i\n", sqlca.sqlcode);
     return;
The output is:
(null) is in department 20
Did you see anything glaringly wrong?
Also, in Pro*C, to stored strings, should I use char [], char *, VARCHAR [], or VARCHAR *?
Thanks,
Eric