Lesson 13 Databases Lesson Objective: Understand the main features of database software Learning Outcome: Clearly identify the uses of database software and use the correct terminology when describing its functions.

Question What’s the point of today’s lesson?

Which software do we use? Database… Microsoft Access NB In the exam DO NOT mention specific software products like those above. Always refer to them as Database and Spreadsheet applications.

Table (FILE) structure NB The exam board prefer to call these things FILES as and not Data Tables … try not to get confused This is the FIELD NAME This is a RECORD Each Record contains at least one FIELD

Key features of databases Storing large amounts of structured data (using data types and validation) Searching for items (queries) Sorting items (queries) Producing Reports

Each table usually has a KEY FIELD. File and Key Field Each table usually has a KEY FIELD. The Key Field is UNIQUE to the record. The Key Field is used to refer to the record in other data tables (FILES)

Two features of key fields They are UNIQUE to the record They are used to REFER to the record in other files

Foreign key when in another table Example Key Field PersonID Name Email Phone Gender SMIC001 Chris Smith cs@hotmail.com 0795551112 M JONA001 Angela Jones aj@yahoo.com 0771234823 F SMIC002 Charlie Smithers chsm@bt.com 0793816944 WILB001 Barry Williams bazw@kms.co.uk 0783746252 OrderID PersonID ProductID Date Dispatched? 100 SMIC001 109 11/9/2008 Y 101 SMIC002 45 13/10/2008 102 JONA001 89 16/10/2008 N 103 125 26/10/2008 Key Field Foreign key when in another table

Flat file / relational database A flat file database does not make use of keys, the same data is often typed in repeatedly (in this example, the continent name) A Relational database uses keys and foreign keys across the different data tables.

Queries Queries are used to limit the number of fields, the number of records and to sort in order. E.g: [Continent] = ‘Europe’ AND [Population] > 40000000