Category : Databases and related files
Archive   : VCRDBASE.ZIP
Filename : NOTES493.TXT

Program Name and Version: VCRDBASE

Author Name: Doctor Disk Drive
Address: Drive Industries
4104 Garrett Place
Colorado Springs, CO 80907

Telephone Number:

Program Classification: dbms

Suggested Donation: $10

Program Description: VCRDBASE is a data base written in Turbo Pascal for the IBM
PC. It can be used to keep record of a personal video library by the reference
of the following data elements:

Movie Name String[20]
Movie Publisher String[20]
Movie Star String[20]
Movie Style (Horror,Comedy,Action,Drama,Misc.)
Movie Sub-Style (Horror,Comedy,Action,Drama,None)
Tape Number Integer
Counter Starter Number Integer
Counter End Number Integer
Tape Speed (S,L,E)
Hard Copy Verification Boolean


VCRDBASE is quite unique in that it uses a Linked List data structure for record
management and sorting. In this data structure, the Header file, HEADER.DAT,
contains the record number of the first alphabetical movie. That movie (the
first alphabetical) contains a forward link and a backward link. The forward
link contains the record number of the next alphabetical movie and the backward
link contains the record number of the preceding record (or in this case, 0
because there is no previous record) Adds are made by placing the record in the
next available file position, and then searching where it belongs among the
records, and adjusting the links to include the new record. It will properly
alphabetize all your movies and is remarkably fast in sorting compared to many
sorting techniques. The data file, DATAFILE.DAT, contains all the movie records
and neither of the files should be renamed, or physically edited because they
are both random access files that are accessed by key only.