ISYS 562 Microcomputer Business

Applications

David Chao

Course ObjectiveTraining Students To Become Developers

• Regular user:– one table or unrelated tables– simple query

• Simple condition– Using form wizard

• Creating forms with one table• Power user

– Database with related tables– Advanced queries

• Calculated field, subtotal, complex condition– Creating forms with many tables– Customizing Access menus and tool bars– Solving problems using the menu options provided by Access

• Developer– Solving problems using the tools beyond the menu options

• VBA programming• Advanced queries with full relational algebra• Creating forms that handle events• Integrated with other systems

Potential Career Opportunities

• Small business application development

• Work group user support– Research group– Attorney office– Small organization

• Consulting

Database Application

• Database application is a program that interacts with the database at some point in its execution.

• It consists of an organized set of menus, forms, reports, business rules, and the database it operates on.

The three components in a database application

1. Presentation – user interface• Menus, forms, reports, etc

2. Processing logic • Business rules

3. Database

Categories of Database Applications

• One-Tier– Legacy online transaction processing– PC database application

• Two-Tier client/server– Client-based presentation.– Processing logic is buried either inside the user

interface on the client or within the database on the server, or both.

• Three-Tier, N- tier– Processing logic is separated from the interface and

database.

Access’s Role

• One-tier PC database application• As a server of a client/server database

application– Windows-based or web-based system

• As a client of a client/server database application

• As a prototyping tool in developing new system– Rapid application development tool

Access Integrated with Other Systems

Other data sources Access Database

ADO/SQL

Excel/Decision Support

System Development Life Cycle

• Definition

• Requirement

• Evaluation

• Design

• Implementation

• Final documentation and testing

• Maintenance

Definition Phase

• Understand exactly what the client wants.• Determine project scope

– Expertise, software tools, estimated cost and time

• Determine feasibility– Can you satisfactorily complete the project within the

expertise, time and budget available

• Document problem definition, scope, feasibility

Requirement Phase

• Determine exactly what the system must do and how well it must perform.

• Interview a representative sample of all stakeholders and formulate system requirements that all stakeholders can agree upon.

• Create a users’ data model.• Create a formal statement of requirements and obtain

client signoff.– State exactly what data will store and process– Describe user interface:

• Forms, reports

– Describe a required level of performance.

Evaluation Phase

• Choose the best development tools.

• Create job descriptions for team members

Design Phase

• Database design– Translate users’ data model into a ER model– Translate the ER model into a relational model

• Database application design– User interface– Application’s flow of control

• Business logic – Design error trapping– Design security features– Prototyping

• Document the design and obtain client signoff

Implementation Phase

• Build the database

• Write the database application program

• Fill the database with data

Testing Phase

• Employ a professional tester• Employ regression testing

– The practice of returning tests from the beginning after the correction of a problem is called regression testing.

• Test the system for functionality, performance, unexpected user behavior and compatibility– Computer, operation system, printer

• Produce final documentation and obtain client acceptance and signoff

Maintenance Phase

• Fixing latent bugs

• Providing enhancements and updates.