Yurttas/PL/DBL/oracle/F/03/Company-B/q10.pc

 1/*  
 2REM
 3REM q10.pc
 4REM
 5REM Find the company with the most employees.
 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 companyname[24];
23} works;
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 companyname 
33    FROM Works 
34    GROUP BY companyname 
35    HAVING COUNT(*) >= ALL (SELECT COUNT(*) 
36                            FROM Works 
37                            GROUP BY companyname);
38
39  EXEC SQL OPEN c;
40
41  EXEC SQL WHENEVER NOT FOUND DO BREAK;
42
43  printf("\ncompanyname\n");
44  for(;;) {
45    EXEC SQL FETCH c INTO :works;
46    printf("%s\n", works.companyname);
47  }
48
49  EXEC SQL CLOSE c;
50
51  EXEC SQL COMMIT WORK RELEASE;
52
53  exit(0);
54}
55
56
57void sql_error(char* msg) {
58  char err_msg[128];
59  int buflen, msglen;
60
61  EXEC SQL WHENEVER SQLERROR CONTINUE;
62
63  printf("%s \n", msg);
64  buflen = sizeof(err_msg);
65  sqlglm(err_msg, &buflen, &msglen);
66  printf("%.*s \n", msglen, err_msg);
67  exit(1);
68}
69
70
71void connect_to_oracle() {
72  /* get your username/passwd from "user_pwd.txt" file */
73
74  FILE *in_file;
75  in_file = fopen("user_pwd.txt", "r");
76  fscanf(in_file, "%s", u_name);
77  fscanf(in_file, "%s", pwd);
78
79  strncpy((char *) username.arr, u_name, UNAME_LEN);
80  username.len = strlen((char *) username.arr);
81
82  strncpy((char *) password.arr, pwd, PWD_LEN);
83  password.len = strlen((char *) password.arr);
84
85  EXEC SQL WHENEVER SQLERROR DO sql_error ("ORACLE error-- ");
86  EXEC SQL CONNECT :username IDENTIFIED BY :password;
87
88  printf("connected to oracle - \n");
89}