Preparing Dynamic SQL statement for inserting in Pro*C

Question

Hi Friends,
From quite some time i am struggling writing Dynamic SQL statement for dynamic insert and update in Pro*C.
Can somebody go through my code and suggest me the rigth way of doing.
Right now it throws an error saying " Error while updating ORA-00904: invalid column name "
Please help me.
Girish.
int main()
EXEC SQL BEGIN DECLARE SECTION;
char *uid ="scott/tiger";
static char sqlstmt[129];
struct /* DEPT record */
int dept_num;
char dept_name[15];
char location[14];
} dept_rec;
EXEC SQL END DECLARE SECTION;
EXEC SQL WHENEVER SQLERROR DO sql_error();
EXEC SQL CONNECT :uid;
dept_rec.dept_num = 50;
strcpy(dept_rec.dept_name,"ADMIN");
strcpy(dept_rec.location,"IN");
strcpy(sqlstmt,"UPDATE dept set DNAME = dept_rec.dept_name where DEPTNO = dept_rec.dept_num");
EXEC SQL EXECUTE IMMEDIATE:sqlstmt;
EXEC SQL COMMIT;
exit(0);
void sql_error()
printf("\nError while updating %s",sqlca.sqlerrm.sqlerrmc);
EXEC SQL ROLLBACK;
}

Answer 1

A bit rusty here but this is how I see it.
Think of it this way ..
all Oracle is going to see is:
UPDATE dept set DNAME = dept_rec.dept_name where DEPTNO = dept_rec.dept_num
Its NOT going to know what dept_rec.dept_name is or dept_rec.dept_num is ..
it doesnt go back and fill in those values.
You need something like
strcpy(sqlstmt,"UPDATE dept set DNAME = \"");
strcat(sqlstmt,dept_rec.dept_name);
strcat(sqlstmt,"\" where DEPTNO = ");
strcat(sqlstmt,dept_rec.dept_num);
printf(sqlsmt); # Just to be sure the update statement look right during testing.