2.1.5 Databases Flashcards
What is a database?
persistent, organised store of data, which can be written or computerised
What is data?
A collection of raw and seemingly meaningless facts, data needs context to become information
What are the key components in a database?
Entities – each recorded items
Attributes – details about the entities
Field – column used to capture attributes
Record – one row of details about an entity
Table – set of fields and records
Primary key – unique number for an entity
What is a flat file database?
A single table of data like a spreadsheet, can have redundant data
What does a regional database do?
Links data/tables together, which removes redundant data and data inconsistency
What does a DBMS do?
Database management system
Allows the user to create a database and manage the data
Allows user to create forms for easier data entry
Allows data to be displayed as graphs and charts
Allows data to be stored in a standard way so it can be accessed by multiple users at same time
Provides a view/interface for the database
What is are queries used for?
To pull specific data from the database, its selection language
What are logic operators?
AND OR NOT, are logic operators and can be combined with = < > !=
What does validation do?
Ensures correct data is inputted to keep database integrity
Specifies the form the data has to be in
What are the types of validation?
Presence check
Checks that something has been entered and that field is not empty
Length check
Checks that it has so many characters in it
Range check
Checks that the value is between a minimum and maximum (only applies to numbers)
Type check
Checks the data type e.g. string, integer, float
Format check
Checks the data follows the specific pattern of characteristics/digits
e.g. dd/mm/yy and not dd/mm/yyyy
What is a report?
Form to add data into the database e.g. name, address, DOB
