Yurttas/PL/DBL/oracle/F/03/PC/q05.pc
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1/*
2REM
3REM q05.pc
4REM
5REM Find those manufacturers that sell Laptops, but not PC's.
6REM
7*/
8
9#include <stdio.h>
10#include <sqlca.h>
11
12#define UNAME_LEN 32
13#define PWD_LEN 16
14
15VARCHAR username[UNAME_LEN]; /* VARCHAR is an Oracle-supplied struct */
16VARCHAR password[PWD_LEN]; /* varchar can be in lower case also. */
17
18char u_name[UNAME_LEN];
19char pwd[PWD_LEN];
20
21struct {
22 char maker[6];
23} product;
24
25void connect_to_oracle();
26void sql_error();
27
28void main(int argc, char* argv[]) {
29 connect_to_oracle();
30
31 EXEC SQL DECLARE c CURSOR FOR
32 (SELECT P.maker
33 FROM Product P, Laptop L
34 WHERE P.model=L.model)
35 MINUS
36 (SELECT P.maker
37 FROM Product P, PC
38 WHERE P.model=PC.model);
39
40 EXEC SQL OPEN c;
41
42 EXEC SQL WHENEVER NOT FOUND DO BREAK;
43
44 printf("\nmaker\n");
45 for(;;) {
46 EXEC SQL FETCH c INTO :product;
47 printf("%s\n", product.maker);
48 }
49
50 EXEC SQL CLOSE c;
51
52 EXEC SQL COMMIT WORK RELEASE;
53
54 exit(0);
55}
56
57
58void sql_error(char* msg) {
59 char err_msg[128];
60 int buflen, msglen;
61
62 EXEC SQL WHENEVER SQLERROR CONTINUE;
63
64 printf("%s \n", msg);
65 buflen = sizeof(err_msg);
66 sqlglm(err_msg, &buflen, &msglen);
67 printf("%.*s \n", msglen, err_msg);
68 exit(1);
69}
70
71
72void connect_to_oracle() {
73 /* get your username/passwd from "user_pwd.txt" file */
74
75 FILE *in_file;
76 in_file = fopen("user_pwd.txt", "r");
77 fscanf(in_file, "%s", u_name);
78 fscanf(in_file, "%s", pwd);
79
80 strncpy((char *) username.arr, u_name, UNAME_LEN);
81 username.len = strlen((char *) username.arr);
82
83 strncpy((char *) password.arr, pwd, PWD_LEN);
84 password.len = strlen((char *) password.arr);
85
86 EXEC SQL WHENEVER SQLERROR DO sql_error ("ORACLE error-- ");
87 EXEC SQL CONNECT :username IDENTIFIED BY :password;
88
89 printf("connected to oracle - \n");
90}