databases

databases

1. advantages of computer databases

   • data can be sorted on several fields
   • data can be searched
   • reports allow data to be extracted
   • data can be inserted straight into the database
   • field types allows the user to control type of data entered

2. Disadvantages of a paper database

   • limited by storage space
   • difficult to search for specific criteria
   • difficult to analyse data
   • changes have to be done manually
   • records can look messy

3. Data types

   • Text
   • Date
   • Integer
     • a whole number
   • Real
     • a decimal number
   • Boolean
     • a value that is true or false
   • Image
     • Holds graphical content

4. Key Terms

   • Record
     • a set of information
   • Primary key
     • A unique piece of information that can identify an individual record
   • Field
     • a piece of information
   • File
     • a table
   • Flat-file database
     • a database with only one table
   • Relational dabasase
     • a table with relationships
     • there are three types of databases
       • one to one
       • one to many
       • many to many
   • Foreign Key
     • the primary key from another table
   • Query
     • a search in a databse
   • Sorting
     • Putting records into a particular order
   • form
     • user friendly method of inserting data
   • Report
     • a professional sheet that is linked to a table or query

5. advantages of a relational database

   • multiple tables
     • with links
   • relationships and links
   • less duplication of data
   • searches, sorting and reports can be carried out/made
   • it can store an item of data one
     • repetition
   • normalise data
     • reduce size
     • prevents repetition