CD Ware Multimedia 1995 May/cd Ware (Juegos) Epimundo.iso/DOS/C/BTCLASS.ZIP/EXAMPLE@.EXE/EXAMPLES.CPP

C/C++ Source or Header | 1992-06-11 | 12.5 KB | 467 lines

/*//////////////////////////////////////////////////////////////////////////
///            ___                                                       ///
///          /_____\                                                     ///
///         |       |                 Copyright (c) 1991                 ///
///         |   R   |                                                    ///
///     ----|_______|----                     by                         ///
///   /------/ | | \------\                                              ///
///  |       | | | |       |      --  Object Resource Group  --          ///
///  |   O   | | | |   G   |                                             ///
///  |       |/   \|       |          4323 Brown Suite 249               ///
///   -------       -------            Dallas,  TX  75219                ///
///   Object Resource Group                                              ///
///                                      [phone]                  ///
///                                                                      ///
///                                    All Rights Reserved.              ///
///                                                                      ///
//////////////////////////////////////////////////////////////////////////*/

//
//  A small example program using the ORG Btrieve classes
//
#include <iostream.h>
#include <iomanip.h>
#include <strstrea.h>
#include <stdlib.h>
#include <string.h>

#include "btdset.hpp"
#include "btskey.hpp"
#include "btdef.hpp"
#include "bttran.hpp"
#include "examples.hpp"


///////////////////////////////////////////////////////////////////////
//////////////////////// Internal Prototypes //////////////////////////
///////////////////////////////////////////////////////////////////////

int CreatePersonDB();
int CreateColorDB();
int GetAndSetColors(PersonDB &personDB, ColorDB &colorDB);
int SetColor(Person &person, ColorDB &colorDB);


///////////////////////////////////////////////////////////////////////
/////////////////////// Class Implementations /////////////////////////
///////////////////////////////////////////////////////////////////////

// Normally class implementations are seperate from main file but
// for convenience of exapmles I have kept them together

// Implementation of PersonDB

// Dump - dumps in person order every one in file
int PersonDB::Dump()
   {
   BT_Key *nameKey = GetKey(0);
   Person person(this);
   int status=nameKey->GetFirst(&person);
   int count=0;

   cout << "\n\n                   -----Dump of PERSON.DB-----\n";
   cout << "\n------------- Name ----------------     --- Color Preference ---\n";

   char buffer[80];
   while (!status)
      {
      count++;

      // the purpose of the brackets is to provide scope for the
      //    ostrstream object
      {
      ostrstream buff(buffer,80);
      buff << setiosflags(ios::left) << setw(35) << person.Name();
      buff << "     " << person.ColorPreference() << endl << ends;
      cout << buffer;
      }

      status=nameKey->GetNext(&person);
      }
   cout << "\nTotal Number of People: " << count << "\n\n";

   if (status == BSTAT_EOF) status=0;
   return status;
   }


// ColorDump - dumps in color order every one in file
int PersonDB::ColorDump()
   {
   BT_SuppKeyDef keyDef;

   int status = keyDef.AddFinalKeySegment(37, 26, BKEY_EXTENDED+BKEY_DUPLICATE,
                     BTYPE_ZSTRING);

   BT_SuppKey *colorKey = GetSuppKey(keyDef);

   Person person(this);
   status=colorKey->GetFirst(&person);
   int count=0;

   cout << "\n\n                -----Color Dump of PERSON.DB-----\n";
   cout << "\n------------- Name ----------------     --- Color Preference ---\n";

   char buffer[80];
   while (!status)
      {
      count++;

      {
      ostrstream buff(buffer,80);
      buff << setiosflags(ios::left) << setw(35) << person.Name();
      buff << "     " << person.ColorPreference() << endl << ends;
      cout << buffer;
      }

      status=colorKey->GetNext(&person);
      }

   cout << "\nTotal Number of People: " << count << "\n\n";

   if (!status || status == BSTAT_EOF)
     status=colorKey->DropKey();
   else
      colorKey->DropKey();    // just drop it anyway but return previous
                // status.
   return status;
   }


// Implementation of ColorDB

// Dump - dumps in person order every one in file
int ColorDB::Dump()
   {
   BT_Key *shadeKey = GetKey(0);
   Color color(this);
   int status=shadeKey->GetFirst(&color);
   int count=0;

   cout << "\n\n             -----Dump of COLOR.DB-----\n";
   cout << "\n----- Color Shade -----    - Preference Count -\n";

   char buffer[80];
   while (!status)
      {
      count++;

      {
      ostrstream buff(buffer,80);
      buff << setiosflags(ios::left) << setw(23) << color.Shade();
      buff << "    " << color.PreferenceCount() << endl << ends;
      cout << buffer;
      }


      status=shadeKey->GetNext(&color);
      }
   cout << "\nTotal Number of Colors: " << count << "\n\n";

   if (status == BSTAT_EOF) status=0;
   return status;
   }


int ColorDB::DumpFromHighestCount()
   {
   // silly example to demonstrate GetPosition and Restore Position
   BT_Key *shadeKey = GetKey(0);
   BT_Key *countKey = GetKey(1);
   Color color(this);
   int count=0;
   int status=countKey->GetLast();

   if (!status)
      {
      ULONG position = GetPosition();
      status = shadeKey->RestorePosition(position, &color);
      // in the above case as only one position was gotton this is also
      // correct:
      //     status = shadeKey->RestorePosition();
      // it will restore to the position of the last GetPosition call

      cout << "\n\n -----Dump of COLOR.DB After Highest Count-----\n";
      cout << "\n----- Color Shade -----    --- Preference Count ---\n";

      char buffer[80];
      while (!status)
     {
     count++;

     {
     ostrstream buff(buffer,80);
     buff << setiosflags(ios::left) << setw(23) << color.Shade();
     buff << "    " << color.PreferenceCount() << endl << ends;
     cout << buffer;
     }

     status=shadeKey->GetNext(&color);
     }
      cout << "\nTotal Number of Colors After Highest Count: " << count << "\n\n";
      }

   if (status == BSTAT_EOF) status=0;
   return status;
   }


// Implementation of Person

// Person(name, personDB) - constructor to connect a file to person and gets
//                the name
Person::Person(char *_name, PersonDB *_personDB) : personDB(_personDB)
   {
   SetName(_name);
   GetRec();
   }

// GetRec() - gets a record associated with objects name
int Person::GetRec()
   {
   BT_Key *nameKey = personDB->GetKey(0);
   int status = nameKey->GetEqual(Name(), &data);
   return status;
   }

// Add() - writes a record to the file
int Person::Add()
   {
   BT_Key *nameKey = personDB->GetKey(0);
   int status = nameKey->Insert(&data);
   return status;
   }


// Implementation of Color

// Color(_name, personDB) - constructor to connect a file to color and get
//                the shade
Color::Color(char *_name, ColorDB *_colorDB) : colorDB(_colorDB)
   {
   SetShade(_name);
   GetRec();
   }

// GetRec() - gets a record associated with objects name
int Color::GetRec()
   {
   BT_Key *shadeKey = colorDB->GetKey(0);
   int status = shadeKey->GetEqual(Shade(), &data);
   return status;
   }

// Add() - writes a record to the file
int Color::Add()
   {
   BT_Key *shadeKey = colorDB->GetKey(0);
   int status = shadeKey->Insert(&data);
   return status;
   }

// Update() - writes a record to the file
int Color::Update()
   {
   BT_Key *shadeKey = colorDB->GetKey(0);
   int status = shadeKey->Update(&data);
   return status;
   }


///////////////////////////////////////////////////////////////////////
/////////////////////////////// MAIN ///////////////////////////////////
////////////////////////////////////////////////////////////////////////


/////////// Btrieve shell is already running, right ? //////////

main()
    {
    int status;
    // create the file
    CreatePersonDB();
    CreateColorDB();

    // open the files
    PersonDB personDB("person.db");
    ColorDB colorDB("color.db");

    if (!personDB.Status() && !colorDB.Status()) // opened successfully
       {
       // poll the user for names and color preferences
       status = GetAndSetColors(personDB, colorDB);
       }

    // print out the results

    if (!status)
       status = personDB.Dump();

    if (!status)
       status = personDB.ColorDump();


    if (!status)
       status = colorDB.Dump();

    if (!status)
       status = colorDB.DumpFromHighestCount();

    ///// The file is closed when the destructor of person is called /////
    if (status)
       cout << "\nProgram terminated with error: " << status << "\n";
    else
       cout << "Program terminated successfully.\n";

    return 0;
    }

// Create - Creates the person file
int CreatePersonDB()
   {
   int status=0;

   BT_Def fileDef(sizeof(PersonData), 0);

   ///// Define the Keys /////

   status = fileDef.AddFinalKeySegment(1, 36, BKEY_EXTENDED+
                          BKEY_MODIFIABLE+
                          BKEY_ALT_SEQUENCE,
                          BTYPE_ZSTRING);
   if (!status)
      {
      ///// set alternate collating sequence to the standard UPPER.ALT /////
      fileDef.SetUpperAlt();

      ///// This actually creates the dataset /////
      status = fileDef.CreateBtrieve("person.db");
      }

   return(status);
   }

// Create - Creates the color file
int CreateColorDB()
   {
   int status=0;

   BT_Def fileDef(sizeof(ColorData), 0);

   ///// Define the Keys /////

   status = fileDef.AddFinalKeySegment(1, 26, BKEY_EXTENDED+
                          BKEY_MODIFIABLE,
                          BTYPE_ZSTRING);
   if (!status)
      status = fileDef.AddFinalKeySegment(27, 2, BKEY_BINARY+
                          BKEY_MODIFIABLE+
                          BKEY_DUPLICATE,
                          BTYPE_INTEGER);
   if (!status)
      {
      ///// This actually creates the dataset /////
      status = fileDef.CreateBtrieve("color.db");
      }

   return(status);
   }

int GetAndSetColors(PersonDB &personDB, ColorDB &colorDB)
   {
   int status=0;

   // loop until no name is given
   char name[36];
   do
      {
      cout << "\nPlease enter person's name (or 'END'): ";
      cin >> name;

      if ( strcmp(name,"END") )
     {
     // attempt to find in file
     Person person(name, &personDB);// constructor gets name if possible
                    // from personDB.

     status = person.Status();    // Because constructors can't return
                    // a status we use status of file
                    // operation.  There are other ways
                    // but this is a simple method.
     if (status == BSTAT_NOTFOUND)
        {
        // this name is not in the file so get color and add it
        status = SetColor(person, colorDB);
        }
     else if (!status)
        {
        cout << name << "'s color preference is " <<
               person.ColorPreference() << "\n\n";
        }
     }
      else
      break;        // No Name - Exit Condition
      } while (!status);

   return status;
   }

int SetColor(Person &person, ColorDB &colorDB)
   {
   char colorPref[26];
   int status=0;

   // enter information
   cout << "Please enter " << person.Name() << "'s Color Preference: ";
   cin >> colorPref;

   // if color was entered continue
   if (strlen(colorPref))
      {
      // capitalize on the color
      strupr(colorPref);

      // this is the goal:
      //    start a transaction
      //    if color record exists in color file,
      //       get it and increment its prefCount by one
      //    else
      //       add the color record to color file and set count to one
      //    insert the person record
      //    if successful
      //       end the transaction
      //    else
      //       abort transaction

      BT_Transaction transaction;
      if (!transaction.Status())        // creation was successful
     {
     Color color(colorPref, &colorDB);    // gets the color record
     if (!color.Status())        // record was found
        {
        color.IncPrefCount();
        status = color.Update();
        }
     else if (color.Status() == BSTAT_NOTFOUND) // record not found
        {
        // note that the constructor already set the shade
        color.SetPrefCount(1);
        status = color.Add();
        }

     if (!status)
        {
        person.SetColorPreference(colorPref);
        status = person.Add();
        }

     // Commit if everything succeeded
     if (!status)
        status = transaction.Commit();
     else
        transaction.RollBack();
     }
      }
   return status;
   }