Database Basics Alan B. Marr, M.D., F.A.C.S. Associate Professor of Clinical Surgery

Objectives Define Database Database Hx Steps of design

What is a Database? A method to store information Easy retrieval Easy update

Database History Flat file –Delimited text –Scan sequential entries –Not easily searchable

Database History Hierarchical Database –Inverted tree –Each file related only to one above or below –No lateral links –Requires repeat data –Hard to search

Database History Network Model –Improvement over hierarchical –Each file with multiple owners –Still can’t relate files to each other

Database History Relational Database –Flexible –No hard structure –File makeup Entries Attributes –SQL

Steps to Developing a Database 1: Planning and Analysis 2: Conceptual design 3: Logical design 4: Physical Design 5: Implementation

Planning and Analysis Anticipate question Literature review Data collection format

Conceptual design Data modeling –Sketch database relationships Entity-relationship diagram

Entity-Relationship Diagram Entity –Person –Place –Thing –Event –Concept Attributes –Descriptors of entities Primary key –Unique descriptor

E-R Example PatientOperation GET Relationship Surgeon Perform

Logical Design Refine conceptual design Normalize data Ensure data integrity

Physical Design Programming logical design Data tables created Forms made and linked Security

Implementation Data entered Database navigated Continual reassessment

Summary Database design important Follow 5 basic steps –1: Planning and Analysis – 2: Conceptual design – 3: Logical design – 4: Physical Design – 5: Implementation