DATABASE AND INFORMATION SYSTEM

DATABASE
- Collection of related files containing records on people, places, or things.
- Prior to digital databases, business used file cabinets with paper files.

ENTITY
- Generalized category representing person, place, thing on which we store and maintain information.
- e.g., SUPPLIER, PART

ATTRIBUTES
. Specific characteristics of each entity.
          -  SUPPLIER name, address
          -  PART description, unit price, supplier


A RATIONAL DATABASE TABLE

RELATIONAL DATABASE
- Organize data into two-dimensional tables (relations) with columns and rows.
- one table for each entity:
          . e.g., (CUSTOMER, SUPPLIER, PART, SALES)
- FIELDS (columns) store data representing an attribute.
- Rows store data for separate RECORDS, or tuples.
- KEY FIELD: uniquely identifies each record.
- PRIMARY KEY:
         . One field in each table
         . Cannot be duplicated
         . Provides unique identifier for all information in any row.