MS Access RDBMS

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MS Access RDBMS
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Database Management System (DBMS)

• A set of programs that permits an organisation
  to
• centralise data
• create database files
• manage them efficiently
• access the data when required
• Using a DBMS, users can
• create new database files
• add, delete, alter, and sort data
• make enquiries and print reports
• The DBMS will
• allow many users to simultaneously access the
  central database
• restrict access for each user to those parts of
  the database that they are entitled to view or
  change
• MS Access has many of the features of a DBMS.

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Basic Components

• Tables
• Forms
• Queries
• Reports

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Tables

• A table for each separate entity
• Design mode allows user to define a data
  structure for the table
• A primary key which must be a unique identifier
  for each record - must be defined. (Access does
  provide an Autonumber function is there is no
  natural unique identifier.

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Forms

• A user-friendly method of entering data for the
  main user(s) of a database
• Usually has one data source, which may be a table
  or a query
• The objects that allow fields to displayed and/or
  modified are known as controls
• Design is very important
• Order of controls
• Layout of controls

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Queries

• Used to create subsets of data held in tables
• Used to combine the contents of more than one
  table
• This is achieved via the relational links that
  are created between tables
• The are several types of query
• Simple select query
• Update query
• Append query
• Delete query
• Crosstab query

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Reports

• Reports are usually used in conjunction with
  queries to produce sorted output satisfying
  particular criteria
• MS Access provides powerful wizards to produce
  reports with various sort, grouping and style
  options.

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Relationships

• The relational database model depends upon the
  creation of relational links between separate
  entities (tables)
• One-to-Many relationship
• For example in a surgery database, a doctor would
  have many patients

• One-to-one relationship
• a doctor would have one expense account