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Case Scenario:   Mary is a small library owner, she has been recording issues by an out of date card system.  She wants to...
First Step: Create the borrowers table                      MemberID created in      MemberID (PK)   order to make        ...
2nd Step: Create the Books table                     BookID created in order                     to make uniqueness     Me...
Problem: !!!!!!! MemberID (PK)                        BookID (PK)                 A Member can hire FirstName       many b...
3rd Step: Create the issues table to resolve   MemberID (PK)                 IssuesID (PK)   BookID (PK)   FirstName      ...
4th Step: Declare the relationships                         1                                 1    MemberID (PK)          ...
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ERD Case scenario

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ERD Case scenario

  1. 1. Case Scenario: Mary is a small library owner, she has been recording issues by an out of date card system. She wants to move into the digital world and wants you to change her card system into an access database…She needs to store information on clients, Issues and books. Books have their own ISBN numbers, but she also wants her own unique numbering system per book.
  2. 2. First Step: Create the borrowers table MemberID created in MemberID (PK) order to make uniqueness FirstName LastName Phone Number Mobile Number Email Address Address City Postal Code
  3. 3. 2nd Step: Create the Books table BookID created in order to make uniqueness MemberID (PK) BookID (PK) FirstName Author LastName Title Phone Number Gender is wrong Edition Mobile Number because books don’t ISBN Email Address have a gender Condition Address Gender City Postal Code
  4. 4. Problem: !!!!!!! MemberID (PK) BookID (PK) A Member can hire FirstName many books and a Author LastName book can be issued Title Phone Number by many members Edition Mobile Number ISBN Email Address Condition Address City Postal Code
  5. 5. 3rd Step: Create the issues table to resolve MemberID (PK) IssuesID (PK) BookID (PK) FirstName DateIssued Author LastName DateReturned Title Phone Number MemberID (FK) Edition Mobile Number BookID (FK) ISBN Email Address Condition Address City Postal Code * FK = Foreign key and is used to link tables together
  6. 6. 4th Step: Declare the relationships 1 1 MemberID (PK) IssuesID (PK) BookID (PK) FirstName DateIssued Author LastName DateReturned Title Phone Number ∞ MemberID (FK) Edition Mobile Number BookID (FK) ∞ ISBN Email Address Condition Address City Postal Code * One Member can have many * One book can be issued many issues, an issue is only made by one times, each issue contains only one member book

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