1/*
2REM
3REM q11.pc
4REM
5REM Find the average hard disk size of a PC for all those
6REM manufacturers that make printers.
7REM
8*/
9
10#include <stdio.h>
11#include <sqlca.h>
12
13#define UNAME_LEN 32
14#define PWD_LEN 16
15
16VARCHAR username[UNAME_LEN]; /* VARCHAR is an Oracle-supplied struct */
17VARCHAR password[PWD_LEN]; /* varchar can be in lower case also. */
18
19char u_name[UNAME_LEN];
20char pwd[PWD_LEN];
21
22struct {
23 char maker[6];
24 int avghd;
25} product;
26
27void connect_to_oracle();
28void sql_error();
29
30void main(int argc, char* argv[]) {
31 connect_to_oracle();
32
33 EXEC SQL DECLARE c CURSOR FOR
34 SELECT P.maker, AVG(hd)
35 FROM Product P, PC
36 WHERE P.model=PC.model
37 AND P.maker IN (SELECT P.maker
38 FROM Product P, Printer R
39 WHERE P.model=R.model)
40 GROUP BY P.maker;
41
42 EXEC SQL OPEN c;
43
44 EXEC SQL WHENEVER NOT FOUND DO BREAK;
45
46 printf("\nmaker\tavghd\n");
47 for(;;) {
48 EXEC SQL FETCH c INTO :product;
49 printf("%s\t%d\n", product.maker,
50 product.avghd);
51 }
52
53 EXEC SQL CLOSE c;
54
55 EXEC SQL COMMIT WORK RELEASE;
56
57 exit(0);
58}
59
60
61void sql_error(char* msg) {
62 char err_msg[128];
63 int buflen, msglen;
64
65 EXEC SQL WHENEVER SQLERROR CONTINUE;
66
67 printf("%s \n", msg);
68 buflen = sizeof(err_msg);
69 sqlglm(err_msg, &buflen, &msglen);
70 printf("%.*s \n", msglen, err_msg);
71 exit(1);
72}
73
74
75void connect_to_oracle() {
76 /* get your username/passwd from "user_pwd.txt" file */
77
78 FILE *in_file;
79 in_file = fopen("user_pwd.txt", "r");
80 fscanf(in_file, "%s", u_name);
81 fscanf(in_file, "%s", pwd);
82
83 strncpy((char *) username.arr, u_name, UNAME_LEN);
84 username.len = strlen((char *) username.arr);
85
86 strncpy((char *) password.arr, pwd, PWD_LEN);
87 password.len = strlen((char *) password.arr);
88
89 EXEC SQL WHENEVER SQLERROR DO sql_error ("ORACLE error-- ");
90 EXEC SQL CONNECT :username IDENTIFIED BY :password;
91
92 printf("connected to oracle - \n");
93}