Using MIS 4e Chapter 5 Database Processing

Course Objectives Objective 1: Understand information system concepts including input, processing, and output, data and information. Objective 2: Understand information system components including hardware, software, databases and telecommunications. Objective 10: Be able to use common personal productivity tools. Objective 11: Be able to create a database using a relational DBMS such as Access. Demonstrate the ability to create reports, queries and join two tables in the DBMS.

What is a database?

What is a database? Database: a collection of data, representing things that exist in the real world, and what we want to know about them.

What is a database? Table Field Columns Rows represents an entity – a person, place, thing, event also called file collection of related rows of data Field describes one characteristic of the entity (name, birth date, phone number, etc.) also called column related fields are grouped into rows

What is the advantage of a database? Businesses use databases to organize and find information efficiently

What is the advantage of a database? Businesses use databases to organize and find information efficiently Why not just use a spreadsheet?

Database or Spreadsheet? Read the Guide on pages 158 - 159 Discuss the questions in a small group (questions 1, 2, 3, 4, 5)

What is the advantage of a database? Why not just use a spreadsheet?

Relational Database By eliminating the duplicate data, we eliminate data integrity problems.

Relational Database Splitting the banking data into separate tables allows each table to represent a single topic or theme. Connections between tables are called relationships.

Relational Database A primary key identifies a unique row in a table

Relational Database A primary key is linked to a matching field on another table to create a relationship The matching field is known as a foreign key

How will a business determine whether they need a database or a spreadsheet? Is the data for long-term storage (as opposed to a work-in- progress)? Do multiple people need access to the data? (at the same time?) Do we need controls on the data to protect against erroneous entries? Is a large part of the data redundant? Database! Are we trying to track a simple list of data? Do we want to easily create charts and graphs? Do we need to crunch numbers and perform automatic calculations? Do we need to create "What-if" scenarios ? Spreadsheet!

How will a business determine what tables and relationships are needed?

Database design using data modeling Users and developers would work together to design a data model Why? A data model represents real business data and real relationships between business entities CHAPTER MEMBER ChapterID Chapter Name Inception Date Advisor URL Member ID First Name Last Name Address City State Postal Code Phone Email Major ….

Database design using data modeling An entity-relationship data model (ERD) shows… entities that will be represented in the database relationships between those entities Entities something we want to track (people, things, places, events) can be a physical object or a logical transaction have attributes that describe its ________. Example? Identifier an attribute whose value is associated with one and only one occurrence of the entity

Database design using data modeling Customer Name Address City State Zip Account # Loan# Loan Type Safe Deposit Box 1 Chad Johnson 85 Bengal Rd Cincinnati OH 62412 91772 51-642 Mortgage 101 2 Chad Ocho Cinco 85 Bengals Road 87-719 Business 105 3 Mike Sorrentino 800 S Main Harrisonburg VA 22807 97525   4 Combs, Sean 50 Dukes Dr 970129 5 Mike Sorrentino (The Situation) 234 6 P.Diddy 50 Duke Dr 930521 51-956 7 John Mellancamp 617 Main St Seymour IN 67844 47-8569 Auto 712 8 Sean Combs 50 Dukes Drive 9423574 9 John Cougar Mellancamp 261 Bluestone Dr 964117 214 10 Mike Sorentino 11 Puff Daddy 22802 87-635

Database design using data modeling Transactions Account SD Box Customer Transactions Account Transactions Customer Account Transactions SD Box Customer Transactions Account SD Box Customer Account Transactions SD Box

Database design using data modeling Customer Account Transactions SD Box Relationships between entities can be… one-to-one – 1:1 one-to-many – 1:N many-to-many – N:M Safe Deposit Box Customer Account Transactions

Database design using data modeling Customer Account Transactions

With a partner, continue creating the data model for the bank example, including the loans. Show entities, identifiers, attributes. Customer Name Address City State Zip Account # Loan# Loan Type Safe Deposit Box 1 Chad Johnson 85 Bengal Rd Cincinnati OH 62412 91772 51-642 Mortgage 101 2 Chad Ocho Cinco 85 Bengals Road 87-719 Business 105 3 Mike Sorrentino 800 S Main Harrisonburg VA 22807 97525   4 Combs, Sean 50 Dukes Dr 970129 5 Mike Sorrentino (The Situation) 234 6 P.Diddy 50 Duke Dr 930521 51-956 7 John Mellancamp 617 Main St Seymour IN 67844 47-8569 Auto 712 8 Sean Combs 50 Dukes Drive 9423574 9 John Cougar Mellancamp 261 Bluestone Dr 964117 214 10 Mike Sorentino 11 Puff Daddy 22802 87-635 This is a credit assignment – make sure everyone gets their name on the sheet that you turn in. Clear and legible writing is required.

Using databases to answer business questions Can we answer these questions?   How many accounts does Sean Combs have? Who is the customer for account 91772? What is John Mellancamp's address? Can we easily see how many customers we actually have? Using queries, we can ask questions of the database results will always be based on current data less time managing data – more time using the information to make business decisions

What are the components of a database application system? To be useful, data in a database table must be easily managed and turned into useful information.

What are the components of a database application system?

What are the components of a database application system? A DBMS is a software program, and a database is a collection of tables, relationships and metadata. Popular DBMS products include: With DBMS, users… create or modify tables and relationships read, insert, modify, or delete data Structured Query Language (SQL), standard language used by most major DBMS administer a database What kinds of tasks might this include?

How do database applications make databases more useful?

How do database applications make databases more useful? Applications allow database processing over the Internet. http://www.Amazon.com

How do database applications make databases more useful? A single database can support multiple users doing many different tasks. must be managed properly to avoid problems: Potential update loss because two users update same data at the same time Possible data conflicts Enterprise DBMS can support thousands of users Many different database applications 24/7 operations DB2, SQL Server, Oracle

How do database applications make databases more useful? Personal DBMS Smaller, simpler applications Fewer than 100 users Microsoft Access is both a DBMS and application development product Fig 5-14 Personal Database System

How is a data model transformed into a database design? Customer Account

How is a data model transformed into a database design? What are the problems with this data? How is the data in this table related? Lessons Table   Name Activity1 Cost1 Activity2 Cost2 Justin Lee Swimming $ 48.00 Amanda Liddle Tennis $ 56.00 Pitch/Catch $ 112.00 Lisa Williams Golf $ 89.00 How many Justin Lee’s are there? What other activities do we offer? What happens to pitch/catch if Amanda Liddle drops out? What if the price of golf lessons changes? Converting a poorly structured table into two or more well-structured tables is called normalization.

How is a data model transformed into a database design? Normalizing the tables by splitting the Student data into a separate table allows each table to describe a single topic or theme. By eliminating the duplicate data, you eliminate data integrity problems. Students   Activities Student ID Name Activity Cost 100 Justin Lee Swimming $ 48.00 127 Amanda Liddle Tennis $ 56.00 152 Lisa Williams Soccer 156 Golf $ 89.00 Pitch/Catch $ 112.00 Student/Activity Student Activity Amt Paid 100 Swimming $ 48.00 127 Tennis $ 56.00 Pitch/Catch 152 Golf $ 89.00 156

What is the user's role in the development of databases? Identify business rules The user’s role is to decide what data should be included and how records should relate to one another be the final judge of how well the database will serve your needs. Do not go forward until the data model is accurate. When is the best time to change the way a database is structured?