source: liacs/db/opdr3/vb1.pc@ 6

/*
 *  vb1.pc
 *
 *  Prompts the user for a branch number,
 *  then queries the branch table for the branch's
 *  address, phone and fax.
 *  2003, Siegfried Nijssen (snijssen@liacs.nl)
 */

#include <iostream.h>
#include <string.h>
#include <stdlib.h>
#include <sqlda.h>
#include <sqlcpr.h>
#include <sqlca.h>

// Define constants for VARCHAR lengths.
#define     UNAME_LEN      20
#define     PWD_LEN        40

//* Declare variables.

EXEC SQL BEGIN DECLARE SECTION;

VARCHAR username[UNAME_LEN];  
VARCHAR password[PWD_LEN];   

// Define a host structure for the output values of a SELECT statement. 
struct
{
  VARCHAR branch_no[10];
  VARCHAR address[60];
  VARCHAR phone[13];
  VARCHAR fax[13];
} branchrec;

//  Input host variable.
VARCHAR branch_no[10];

EXEC SQL END DECLARE SECTION;

// Declare error handling function. 
void sql_error(char *msg)
{
  char err_msg[128];
  size_t buf_len, msg_len;

  EXEC SQL WHENEVER SQLERROR CONTINUE;
   /* after executing this line, sql_error is no longer used as
    * error handling function. In this way, infinite 
    * recursion is avoided if the next SQL statement
    * in this function fails.
    */

  // Print the error message:
  cout << msg << endl;
  buf_len = sizeof (err_msg);
  sqlglm(err_msg, &buf_len, &msg_len);
  cout << msg_len << "*" << err_msg << endl;

  // Make sure the database is consistent:
  EXEC SQL ROLLBACK RELEASE;
  
  // Stop the program.
  exit(EXIT_FAILURE);
}

void main()
{
  char temp_char[32]; /* strings are of type VARCHAR in Oracle and not \0
                       * terminated. We use this temporary variable
                       * whenever a \0 terminated string is necessary.
                       */

  
  cout << "Enter your ORACLE username: " << endl;
  cin >> temp_char;
  
  /* Connect to ORACLE--
   * Copy the username into the VARCHAR.
   */
  strncpy((char *) username.arr, temp_char, UNAME_LEN);

  // Set the length component of the VARCHAR. This is always required! 
  username.len = (unsigned short) strlen((char *) username.arr);
  
  cout << "Enter your ORACLE password: " << endl;
  cin >> temp_char;

  // Copy the password.
  strncpy((char *) password.arr, temp_char, PWD_LEN);
  password.len = (unsigned short) strlen((char *) password.arr);

  // Register sql_error() as the error handler. */
  EXEC SQL WHENEVER SQLERROR DO sql_error("ORACLE error--\n");

  /* Connect to ORACLE.  Program will call sql_error()
   * if an error occurs when connecting to the default database.
   */
  EXEC SQL CONNECT :username IDENTIFIED BY :password;

  cout << "Connected to ORACLE as user: " << username.arr << endl;

  /* Loop, asking for branch IDs */

  do {
    
    cout << "Enter branch number: (0 to quit) ";
    cin >> temp_char;
    
    if ( strcmp ( temp_char, "0" ) == 0 )
      break; // stop the while loop
    
    // Fill in branch_no that we will use in the query.
    strncpy((char *) branch_no.arr, temp_char, 10);
    branch_no.len = (unsigned short) strlen((char *) branch_no.arr);

    /* Branch to the notfound label when the
     * 1403 ("No data found") condition occurs.
     * Although labels are required here, this does not mean that
     * using labels in general is good programming practice!
     * You are only allowed to use labels as target for an SQL GOTO statement.
     */
    EXEC SQL WHENEVER NOT FOUND GOTO notfound;

    EXEC SQL SELECT branch_no, address, phone, fax
             INTO :branchrec
             FROM Branch
             WHERE branch_no = :branch_no;

    /* Print data.
     * The branchrec.address VARCHAR is not \0 terminated. We have
     * to make it \0 terminated first to print it.
     */
    branchrec.address.arr[branchrec.address.len] = '\0';        
    cout << "Address: " << branchrec.address.arr << endl;
        
    branchrec.phone.arr[branchrec.phone.len] = '\0';    
    cout << "Phone: " << branchrec.phone.arr << endl;
        
    branchrec.fax.arr[branchrec.fax.len] = '\0';        
    cout << "Fax: " << branchrec.fax.arr << endl;

    // Continue the loop,  the other lines in this loop are
    // for error handling:
    continue;

notfound:
    cout << endl << "Not a valid branch number - try again." << endl;

  }
  while ( true );
   // continue after an invalid branch number.

  // Disconnect from ORACLE. 
  EXEC SQL ROLLBACK WORK RELEASE;
  
  exit(EXIT_SUCCESS);
}