Entity Relationship Diagram

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Entity Relationship Diagram The bellow diagram is what is refered to as an "Entity Relationship Diagram". Its purpose is to show the relationship between different data in the hotel management program , and the actions that are performed on it. And how data from different objects relate to each other. Legend The Data Entities represent data that will need to be stored on the system, in general terms. The Relationships represent actions that will occur to the Data Entities, or Weak Entities. The Weak Entities represent data that does not exist, except in relation to a Data Entity. Data Dictionary Below is a data dictionary used to demostrate how data will be represented in the computer system, and how different modules are inter…show more content…
Outgoing Phone Number = Phone Number * Represents a call made from a room.* Password = STRING(8) * An position to maintain the password of the user.* Phone Call = Bill To + Outgoing Phone Number + Start Time + Stop Time + Cost of Phone Call * Represents a phone call made from a certain room. * Phone Number = [ 0 | 1 | .. | 9] + '- ' + [000 | 001 | ... | 999 ] + '- ' + [000 | 001 | ... | 999 ] + '- ' + [0000 | 0001 | .... | 9999] * Represents a phone number.* Phone Service = {Phone Call} * A List of Phone Usages.* Price = $ + INT + [00 | 01 | .. | 99] * A Field which represents the price for a Menu Item.* Price Per Night = $ + INT + '. ' + [00 | 01
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