Database Design and SQL

Connie Wagner, Instructor

Class

• Syllabus• Schedule• Contact information

Covering In Class

• MS Access – developer’s view• Proper steps in setting up a database• SQL statements

Relational Databases

• Types of Databases– Flat• Word tables, Excel, etc

– Relational• No redundancy• Tables are related

Database Systems

• Three components– Data– Structure– Technology to store and retrieve

• Examples– Telephone book– Dictionary

Data

• All around us• Needs to be shared – easily accessed• Needs to be current• Needs to be organized - structured• Needs to be easily understood• MUST be accurate

Structure

• Must be identified– Entities (fields) that describe the reality of the

business– Attributes (properties) of these entities– Roles of the attributes– Relationships between the entities– Behavior of the entities and attributes when the

data changes

Structure

• Importance of analysis– Primary objective is to know the business and

design a model– Review current procedures, reports and forms

Structure

• Importance of analysis– Work with end-users • Ask what is currently working• Ask if you would change anything, and if so, what

would it be• What is their level of expertise• Any special requirements

– Current/Planned hardware• Server• End-user systems

Technology - Using a Database Application w/ Data Managed by a Database Server

• Create a service that owns the data– Manages how it is accessed to avoid conflicts

• Ensure all applications access data through this service

Complex Application w/Multiple Options for Each Layer

• Stores information in company database• May need to run disconnected from the main

system• Connected to the network– Attached to central database and stores data in

database• Not connected to network– Stores data locally

Interfaces/Connections

• ODBC – open database connectivity– Programming layer• RDO – old• ADO – current (active data object)

• OLE DB – object linking and embedding database

• Others

Interfaces/Connections

• Efficiency– Fast processing

• Dependable