Databases by Toby Stack

The purpose of this article is to give you a quick introduction into databases. Rather than being an tutorial on how to design and build databases this is more of an overview of some key database concepts that will hopefully give you enough of an understanding so you don't feel completely lost when people start talking about databases, or to give you a starting point for your own further studies.

All businesses store large amounts of data, they hold data about staff, data on customers, data on suppliers, data on stock, data on finance, many even store data about other bits of data! Just think of any business you have been involved with, it is almost inconceivable that a business could exist with out some form data storage ranging from the ubiquitous filing cabinet to the (now somewhat rare) filofax. Although the examples given are paper based, more and more businesses are turning towards computer based systems to handle their data.

Just about any system that stores large amounts of similar data should be stored in an computerized database, to give a classic example the storage of contact details is the perfect use of a database. Unlike a physical format such as an address book and even a similar electronic format like a spreadsheet, a database allows contact details to be searched and manipulated with the minimum of effort, it will also allow you to connect up related databases. This is one of they key benefits to having a database, no one would bother to store data unless they were going to do something with it and a database will allow an organization to do this efficiently and even open up new ways of using data.

Programs that run databases are known as database management systems or DBMS for short, there are a large number of DBMS and many of them have quite a different look and feel to them however they are almost always based on relational database theory and once you understand that DBMS tend to make sense.

Tables

Databases store all their data in tables consisting of rows and columns. Each row in a database represents one collection of data known as a record, each column contains a single item of data relating to the record. To give an example, in a database for contact details each row would relates to a single person and the columns would be each bit of data relating to that person.

database table

This table shows three records in a database of contact details, for each record we record the CustomerID, First Name, Surname, Title, Street, Post Code, Landline, Mobile and email of a person.

Queries

Because data in a database is structured it makes it very easy to search for information, each DBMS will provide a different way of interacting with the database but generally the overall principle is the same. The most common situation is where you need to find out one bit of information by using another, for example finding a phone number based on a name. As well as having their own particular interfaces most DBMS support SQL, SQL is text based way of getting information from databases and is used extensively in on-line and corporate databases. In most cases an end user will not need to know SQL, however if you are involved with the making or running of a database it is well worth while learning the basics of SQL as it will help you understand how a database works.

As well as helping with managing a business, databases also power many modern websites therefore if you are involved with a web based business it is quite likely that you will end up using some form of on-line database. Thankfully on-line databased are to all extents identical to any other database with the only big difference being that rather than using a DBMS style interface you will probably use some form of web based interface or content management system.