Types of Database
It is important not to confuse a database with the software that handles it. Software is needed to make use of the data in the database. The software may be specially written in a programming language like C++ or it might be part of a Database Management System (DBMS). You do not normally buy database software applications off the shelf because each business is different and therefore has specific needs regarding its data.
The DBMS will enable a user to perform specific actions such as:
- Creating an empty database
- Deleting an entire database
- Creating and deleting tables
- Inserting new records into tables
- Updating and deleting records
- Being able to extract data sets
- Being able to produce reports that summarise the data
- Being able to process the data to create new data
There are many database management systems that are either commercial products or free open source applications. Examples include:
- MySQL - A very popular, free open source system, widely used on website including this one
- Access - Included in some versions of the Microsoft Office suite
- Base - Part of the free Opeen Office suite
- Oracle - A multi-user enterprise level database management system. Widely used in industry
Use of Data Handling Software
The Data Handling software that you will be most familiar with is MS Access although you may have experience of others the mechanics remain the same...
- Field – this is a single piece of data about something – you could have a name field, a phone number field, a national insurance number field. Fields can have rules attached to them to prevent the wrong data being entered.
- Record – this is a collection of fields all about something – when you searched Amazon for a book, it will have returned a record that has the name of the book, author, date of publication, cost and so on. All the fields are about that one item.
- Table – this is a collection of records all about something – Amazon will have different tables for different types of product. A book table might store records which have authors, dates of publication, costs and so on. A DVD table might store records which have titles, actors, duration, genre and so on. So each type of product is stored in a different table.
- Database – this is a collection of tables. A relational database can link together different tables which have fields in common using relationships. The relationships use the Primary Key from one table as a Foriegn Key in the new table, thereby helping us link the data and reducing redundancy.
- Primary Key - used to link tables together and reference a record, when used in a relational database the Primary Key becomes the Foriegn Key in a linked table.