Chapter 4 Database Processing Copyright © 2013 Pearson Education, Inc. Publishing as Prentice Hall 4-1

Learning Objectives Q1. What is the purpose of a database? Q2. What are the contents of a database? Q3. What are the components of a database application system? Q4. How do data models facilitate database design? Copyright © 2013 Pearson Education, Inc. Publishing as Prentice Hall 4-2

Learning Objectives Q5. How is a data model transformed into a database design? Q6. What is the user’s role in the development of databases? Q7. How can the intramural league improve its database? Copyright © 2013 Pearson Education, Inc. Publishing as Prentice Hall 4-3

What is the purpose of a database? Databases keep track of things Lists of data and themes – Single theme (concept) Can be managed using a spreadsheet – Multiple themes (concepts) Require databases Copyright © 2013 Pearson Education, Inc. Publishing as Prentice Hall 4-4

What is the purpose of a database? Figure 4-1 List of Student Grades in a Spreadsheet Figure 4-2 Student Data in a Form, Data from a Database Copyright © 2013 Pearson Education, Inc. Publishing as Prentice Hall 4-5

What are the contents of a database? Database – self-describing collection of integrated records Characters (bytes) Columns (fields) Rows (records) Tables (files) Figure 4-3 Elements of the Student Table (also called a file) Copyright © 2013 Pearson Education, Inc. Publishing as Prentice Hall 4-6

What are the contents of a database? What are the relationships among rows? – Key A value in one row of one table that appears as a value in another row of another table – Primary key A value that identifies a unique row in a table – Foreign key A value in one table that appears as a primary key in another table to which it relates Copyright © 2013 Pearson Education, Inc. Publishing as Prentice Hall 4-7

What are the contents of a database? Relational Database Figure 4-6 Examples of Relationships Copyright © 2013 Pearson Education, Inc. Publishing as Prentice Hall 4-8

What are the contents of a database? Metadata – Data that describe data Copyright © 2013 Pearson Education, Inc. Publishing as Prentice Hall 4-9

What are the components of a Database Application System? Database DBMS – Create/Administer – Processing Language Database Applications Figure 4-8 Components of a Database Application System Copyright © 2013 Pearson Education, Inc. Publishing as Prentice Hall 4-10

What are the components of a Database Application System? Database v. Database Management Systems (DBMS) – Databases are self-describing collections of integrated records – DBMS are software used to create, process, and administer databases Copyright © 2013 Pearson Education, Inc. Publishing as Prentice Hall 4-11

What are the components of a Database Application System? Database Management Systems (DBMS) – Creating the database and its structures – Processing the Database Read, insert, modify, or delete data Structured Query Language (SQL) – Administering the database  Database Administrator (DBA) Copyright © 2013 Pearson Education, Inc. Publishing as Prentice Hall 4-12

What are the components of a Database Application System? Database Management Systems (DBMS) Figure 4-10 Summary of Database Administration Tasks Copyright © 2013 Pearson Education, Inc. Publishing as Prentice Hall 4-13

What are the components of a Database Application System? Database Applications – Collection of: Input For Apps Report APPS Query Apps Application programs Copyright © 2013 Pearson Education, Inc. Publishing as Prentice Hall 4-14

What are the components of a Database Application System? Multi-user Processing – Lost update problem Figure 4-14 Applications Running on a Web Server Copyright © 2013 Pearson Education, Inc. Publishing as Prentice Hall 4-15

What are the components of a Database Application System? Categories of DBMS – Enterprise DBMS 1000’s of users – Work Group DBMS Less than 100 users (server systems) – Personal DBMS 1 user (personal computers) Copyright © 2013 Pearson Education, Inc. Publishing as Prentice Hall 4-16

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8/22/2011 Copyright © 2013 Pearson Education, Inc. Publishing as Prentice Hall 18

8/22/2011 Copyright © 2013 Pearson Education, Inc. Publishing as Prentice Hall 19 A data dictionary contains data about each file in the database and each field in those files

What are the components of a Database Application System? Database DBMS Database Application(s) Copyright © 2013 Pearson Education, Inc. Publishing as Prentice Hall 4-20

How Do Data Models Facilitate Database Design? Figure 4-16 Database Design Process Copyright © 2013 Pearson Education, Inc. Publishing as Prentice Hall 4-21

How Do Data Models Facilitate Database Design? Entities (Records) – Something users want to track Attributes (Fields) – Describe characteristics of entities – Identifier Relationships – Entities linked to each other Copyright © 2013 Pearson Education, Inc. Publishing as Prentice Hall 4-22

How Do Data Models Facilitate Database Design? Entity Relationship (E-R) Diagrams – Maximum Cardinality Figure 4-19 Entity Relationships, Diagram Version1 Figure 4-20 Entity Relationships, Diagram Version2 Copyright © 2013 Pearson Education, Inc. Publishing as Prentice Hall 4-23

How Do Data Models Facilitate Database Design? Entity Relationship (E-R) Diagrams – Maximum and Minimum Cardinality Figure 4-21 Entity Relationships, Diagram Version 3, Minimal Cardinality Shown Copyright © 2013 Pearson Education, Inc. Publishing as Prentice Hall 4-24

How Is a Data Model Transformed into a Database Design? Normalization – Converting poorly structured tables into two or more well-structured tables Design considerations – 1:N relationships – N:M relationships Copyright © 2013 Pearson Education, Inc. Publishing as Prentice Hall 4-25

How Is a Data Model Transformed into a Database Design? Normalization – Data integrity problems – Normalizing for data integrity Copyright © 2013 Pearson Education, Inc. Publishing as Prentice Hall 4-26

How Is a Data Model Transformed into a Database Design? Design considerations – 1:N relationships – N:M relationships Copyright © 2013 Pearson Education, Inc. Publishing as Prentice Hall 4-27

What is the User’s Role in the Development of Databases? Users are final judges as to the data in the database Users should review the data models before developing the database Copyright © 2013 Pearson Education, Inc. Publishing as Prentice Hall 4-28

How Can the Intramural League Improve Its Database? Opening Vignette: – Intramural problems Process problem (addressed in Chapter 5) Database problem Copyright © 2013 Pearson Education, Inc. Publishing as Prentice Hall 4-29

How Can the Intramural League Improve Its Database? Database Revision 1 – Update “Team” table with “Season” field – Rename the table “Team_Season” Figure 4-28 League Database Revision 1, Team_Season Table Copyright © 2013 Pearson Education, Inc. Publishing as Prentice Hall 4-30

How Can the Intramural League Improve Its Database? Database Revision 1 – Normalization is needed Figure 4-30 League E-R Diagram Revision 1 Copyright © 2013 Pearson Education, Inc. Publishing as Prentice Hall 4-31

How Can the Intramural League Improve Its Database? Database Revision 2 – E-R Diagram Figure 4-32 League E-R Diagram Revision 2 Copyright © 2013 Pearson Education, Inc. Publishing as Prentice Hall 4-32

How Can the Intramural League Improve Its Database? Opening Vignette: – Intramural problems Process problem (addressed in Chapter 5) Database problem Copyright © 2013 Pearson Education, Inc. Publishing as Prentice Hall 4-33

Ethics Guide Nobody Said I Shouldn’t – Chris restored his company’s database on his personal computer – Was this illegal? Unethical? Neither? – Discussion Questions Copyright © 2013 Pearson Education, Inc. Publishing as Prentice Hall 4-34

Conclusion Q1. What is the purpose of a database? Q2. What are the contents of a database? Q3. What are the components of a database application system? Q4. How do data models facilitate database design? Copyright © 2013 Pearson Education, Inc. Publishing as Prentice Hall 4-35

Conclusion Q5. How is a data model transformed into a database design? Q6. What is the user’s role in the development of databases? Q7. How can the intramural league improve its database? Copyright © 2013 Pearson Education, Inc. Publishing as Prentice Hall 4-36

Copyright © 2013 Pearson Education, Inc. Publishing as Prentice Hall 4-37