SQL

SQL, or to use its full name 'Structured Query Language' is a database technology designed to simplify the analysis and retrieval of data. Although SQL can be used to actually create new databases and tables, the parts where the data is actually stored, it is probably best known for its ability to deliver business data very quickly.

Let's take a look at how it may work. As a business owner I am sure you have a number of spreadsheets into which you store your customer's details such as their addresses and telephone numbers. You will probably have a spreadsheet (or many more) for storing details of customer orders - these might include the items bought and the date. How long would it take you to draw up a list of all the customers who bought your top selling product in the last 6 months?

If you have a large number of customers this is going to be a problem as you will have to filter through every order and work out who ordered it and when. If those spreadsheets were actually loaded into a database as tables, then you could write a piece of SQL to retrieve that data. SQL looks a bit like English and bit like a 'computer language' so it is actually popular with both technical and non-technical people.

In our example, we would probably write a piece of SQL that looks like this:

SELECT * from Customers WHERE (Orders.Product = "Top Selling Product") AND (Orders.Date IS BETWEEN Now and 6 Months Ago)

Note: we have simplied a bit of this so please don't email in to tell us it is technically incorrect! Essentially what the SQL says it to get everything (denoted by the * asterisk) from our Customers table where in the Orders table the product is our top selling product and the date of the order is within the last six months.

This piece of SQL would take a few seconds to run and would bring back all the key business information you need. As the number of tables grows larger and larger and the number of pieces of data increases SQL becomes even more important. Without it we wouldn't be able to produce nice reports or locate those customers who are late paying... the list is endless.