Chapter 13

Chapter 13 – Databases

Key words:

• Database – a collection of data stored in a logical and ordered manner. Data bases can also be use on paper and electronically.
• Relational database –  Many tables together that have a relationship with each other or otherwise linking to other databases.
• Flat file database – single table, no links
• primary key – the main key – unique (pieces of data) field that can search things quickly . This allows you to create relationships between databases
• foreign key  – allows links between databases – not unique.
• CSV – Comma Separated Validation. You can import the data from CVS files to a Microsoft access file, (CVS files are usually text form and come in apps like excel).
• Query – a method of searching a database
• SQL – Specialised programming language for maintaining a database
• Query by example – a method of search a database by stating criteria to be searched

Examples of uses of databases:

• Bookstore/Library – bar code on the book for stored data – who borrowed the book, due date, etc.
• School records – data about students – parents occupation, illness, year/grade, etc.
• Exam results – candidates exam results

What is a Database?

• A database is a collection of data stored in a logical and ordered manner.  Databases can be both electronic or paper based
• All databases have a structure that allows data to be held within them to be stored in a logical and orderly manner
• Data is stored in tables consisting of records and fields
• A databases with a single table is known as a flatfile database.  Databases with multiple tables are known as relational databases
• A record is a collection of data about one single item in a database
• Each database field must be given a datatype
• Tables need a primary key so records are unique and can be identified quickly
• A search for data is known as a query
• SQL is a programming language that is used to maintain databases to create queries.

Datasheet view:

Design View: