Categorieën: Alle - databases - processing - information - redundancy

door tyler baskerville 13 jaren geleden

256

notes about databases

A database is a structured collection of information stored on a computer system, designed to efficiently manage and retrieve data. In relational databases, multiple tables are linked to reduce data redundancy, minimize entry errors, and save storage space.

notes about databases

notes about databases

three ways you can organise data a.k.a data processing

data types



  • autonumber = numbers that are automatically generated for each record. autonumber is normally used for key feilds to make sureeach is deiffrent.
  • number = numeric values these can be intergers (whole numbers) or decimals.
  • Alphanumeric/text = short valuescontaining numbers and letters
  • currency = monetary values
  • date/time = dates and time
  • object/image = files such as digial photos
  • logical/boolean = yes/no values
  • limited choice = where values are limtied to those in a drop-down list
  • present the facts in a interesting way. for example print a report or a graph
    work out new facts from the ones you alresdy have.for example work out an average from a lonf list of number s
    organise facts into a simple order like words in a dictoinary or names in a phone book

    relational database

    a datbase containinh two or more tables that are linked to each other. this overcomes problems problems of data redundancy, resting in fewer entry errors and reduce storage space

    data processing

    when data is organised to make it more useful it is called information
    RAW facts and figures in a disorganised state are called DATA

    definition

    a data base is a structured collection of info stored on a computer system

    key feild

    also called primary key. a feild in a table which uniquely identifie each record in tht table

    remove duplicate data makes thing quicker and faster ruduces storage space