Yurttas/PL/DBL/oracle/F/03/PC/q10.pc

 1/*  
 2REM
 3REM q10.pc
 4REM
 5REM Find the maker of the printer with the fastest processor
 6REM among all those PC's that have the smallest amount of RAM.
 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} smallram;
25
26void connect_to_oracle();
27void sql_error();
28
29void main(int argc, char* argv[]) {
30  connect_to_oracle();
31
32  EXEC SQL
33    CREATE VIEW SmallRam(model,ram)
34      AS (SELECT model, ram
35          FROM PC
36          WHERE ram IN (SELECT MIN(ram)
37                        FROM  PC));
38
39  EXEC SQL DECLARE c CURSOR FOR
40    SELECT P.maker
41    FROM Product P, PC C, SmallRam S
42    WHERE P.model=C.model
43      AND C.model=S.model
44      AND C.speed IN (SELECT MAX(speed)
45                      FROM PC, SmallRam S
46                      WHERE PC.model= S.model);
47
48  EXEC SQL OPEN c;
49
50  EXEC SQL WHENEVER NOT FOUND DO BREAK;
51
52  printf("\nmaker\n");
53  for(;;) {
54    EXEC SQL FETCH c INTO :smallram;
55    printf("%s\n", smallram.maker);
56  }
57
58  EXEC SQL CLOSE c;
59
60  EXEC SQL COMMIT WORK RELEASE;
61
62  exit(0);
63}
64
65
66void sql_error(char* msg) {
67  char err_msg[128];
68  int buflen, msglen;
69
70  EXEC SQL WHENEVER SQLERROR CONTINUE;
71
72  printf("%s \n", msg);
73  buflen = sizeof(err_msg);
74  sqlglm(err_msg, &buflen, &msglen);
75  printf("%.*s \n", msglen, err_msg);
76  exit(1);
77}
78
79
80void connect_to_oracle() {
81  /* get your username/passwd from "user_pwd.txt" file */
82
83  FILE *in_file;
84  in_file = fopen("user_pwd.txt", "r");
85  fscanf(in_file, "%s", u_name);
86  fscanf(in_file, "%s", pwd);
87
88  strncpy((char *) username.arr, u_name, UNAME_LEN);
89  username.len = strlen((char *) username.arr);
90
91  strncpy((char *) password.arr, pwd, PWD_LEN);
92  password.len = strlen((char *) password.arr);
93
94  EXEC SQL WHENEVER SQLERROR DO sql_error ("ORACLE error-- ");
95  EXEC SQL CONNECT :username IDENTIFIED BY :password;
96
97  printf("connected to oracle - \n");
98}