Advantages of a Database?
- Data can be accessed quicker
- It can be easily transformed into a new piece of data
- Can easily sum up the total
- A single database can be shared internationally - for example: a database for a video game which has shops across the world
- Data Validation( an automatic computer check to ensure that the data is sensiuble and reasonable. it does not check the accuracy of the data)- the database can be set up to accept a certain data type
- It is well organised- can sort data quickly
- Flexible reporting - can access certain data
Database Management Systems
- It is a piece of software that sits between the application( for example: microsoft access) and the file system( data)
- The purpose is to allow databases to be made, used and maintained.
- It has the ability to check for data inconsistencies
- It can reduce the amount of repeated data( database's role is to ensure data is only stored once)
- It can access data from different tables in the file system by linking these tables to one another
- It adds security to keep the data secured
- multiple users accessing data at the same time
Foreign key- used to link 2 tables together so that we have access to both the tables information without having to repeat data
Table- a collection of database fields designed to be used together
Database: A collection of organised data that allows access, retrieval, and use of data.
Field- A category of information in a database
Query-A database object which allows you tolocate multiple reocrds which match the specified criteria
Record- collection of fields that appear as a row in a database or table
Validation- an automatic computer check to ensure that the data entered is sensible & reasonable. It does not check the accuracy of data
Relationship: A link between 2 or more tables based on a common field
One to many- an entity relationship in which a record in a table relates/matches to lots of records in another table
Data type- Determines what sort of data can be stored in text.
Integer- a whole number( both positive and negative) and zero
Boolean- data type used to represent a single true or false value
Data item- one piece of data
Primary Key- a field that uniquely identifies a given entity in a table
AutoNumber- a data type that automatically adds a unique field value to each record in a table
Sorting- Arranging data in a specified data
Date/Time- a data type that only accepts DD/MM/yy
Flat-file database- A database that can only work with one table at a time
Relational Database- Database which can have multiple tables with information on a specific subject. Each of those tables can be linked.
Structured Data- Data or information displayed in titled columns and rows that can easily be ordered and processed
Unstructured Data- Data that has no identifiable structure- a complete lack of organisation
Lookup Wizard- A data type that allows the user to chose from a set of predefined values.