GCSE Computer Science: Database

Descrição

Mapa Mental sobre GCSE Computer Science: Database, criado por MegzRevision em 04-01-2015.
MegzRevision
Mapa Mental por MegzRevision, atualizado more than 1 year ago
MegzRevision
Criado por MegzRevision aproximadamente 10 anos atrás
43
2

Resumo de Recurso

GCSE Computer Science: Database
  1. Entity
    1. An entity is a person or physical thing about which data is held in a database
    2. Field
      1. An individual box in the data table
        1. Table = The whole thing
      2. Record
        1. An entire row of data
        2. Database management system / DBMS
          1. Allows you to create a table
            1. Componants
              1. Tables
                1. Forms
                  1. Queries
                    1. Reports
                      1. Modules
                        1. Program within an application that performs a specific task which cannot be done by simply making a query or report
                    2. Datatypes
                      1. Text
                        1. Integers
                          1. Numbers with a decimal
                            1. Dates
                              1. Currency
                                1. Yes/No fields
                                2. Primary Key
                                  1. One field is designated as the p.k
                                    1. Each record must have a different value in the p.k
                                      1. Uniquely identifies the record
                                      2. Validating Fields
                                        1. Minimise errors when data is entered into the database
                                          1. Specifying a rule that the data must obey
                                            1. Range check
                                              1. Type check
                                                1. e.g. number
                                                2. Presence check
                                                  1. Data entered in the field
                                                  2. Format check
                                                    1. List check
                                                      1. Must be item on predefined list
                                                  3. Data Redundancy
                                                    1. Holding more data than necessary
                                                      1. Takes time and space
                                                        1. Can result in inconsistent data
                                                        2. Each entity has an attribute
                                                          1. Attribute = Field in the table which describes the entity
                                                            1. One-to-one
                                                              1. e.g. husband/wife
                                                              2. One-to-many
                                                                1. e.g. mother/children
                                                                2. Many-to-many
                                                                  1. e.g. pupils/subjects
                                                            2. Separation of Data
                                                              1. Data held about various entities are held separatly from the applications that use it.
                                                                1. e.g. many departments in a school can look at or use the data
                                                                2. Reduces data redundancy
                                                                  1. Data is consistent
                                                                    1. Saves storage
                                                                    2. Database
                                                                      1. Persistent, organised store of data
                                                                        1. Persistent = Data stored on a non-volatile storage device
                                                                          1. Organised = Structured into tables
                                                                          2. Allows separation of data between applications and the database
                                                                            1. Allows multiple applications to use a single database
                                                                              1. Can allow many users to simultaneously access the data and it's applications
                                                                                1. Provides security in terms of access rights
                                                                                  1. Can provide automatic backups
                                                                                  2. Reports
                                                                                    1. Useful feature of a DBMS
                                                                                      1. Reports are produed based on queries
                                                                                        1. When a user asks for a report based on a query, the query will automatically be run first using the latest data, so the report is up-to-date

                                                                                        Semelhante

                                                                                        Quiz Sobre Genética
                                                                                        Marerodrigues
                                                                                        Como Estudar Matemática
                                                                                        Alessandra S.
                                                                                        Revisão Para o ENEM em 20 dias
                                                                                        Alessandra S.
                                                                                        Prazos – TJ – SP
                                                                                        andre.cuevas
                                                                                        50 frases, palavras e expressões mais usadas em Francês
                                                                                        Miquéias M
                                                                                        PSICOLOGIA DA GESTALT
                                                                                        eleuterapara
                                                                                        Seguridade Social 3 - Organização e Princípios Constitucionais
                                                                                        André Cavallini
                                                                                        Direito Constitucional e Administrativo
                                                                                        GoConqr suporte .
                                                                                        REVISÃO DO ENS FUNDAMENTAL
                                                                                        Paulo César R. Silva
                                                                                        Sistema Único de Saúde
                                                                                        Vanessa Campos
                                                                                        Botânica
                                                                                        STELA FAUSTINO