What is SQL?

SQL which stands for structured query language is a computer language, the language is used to take care of relational databases. Using SQL, we can build relational databases and execute various operations on the data within. A relational database is a database made up of tables, these tables include information that is linked to other tables in the same database, the link between the tables makes the database relational.

What Can SQL Be Used For?

SQL is the language used to structure and manage data located within relational database management systems. Using SQL data can be input, deleted, requested, updated, and reorganized. The access to data within relational databases can also be controlled using SQL.

As an example let's say we had a database of customer information, and the database held 2 different tables, 1 for the customer's personal data such as the address details, etc, and 1 for orders placed. Using SQL we can write up 1 query to show us all of the customer's details and the customer's order details, and if we wanted to output this information inside of the software, we could do so. As stated above this information can then be updated, deleted, and reorganized. This is great for companies to store information.

Using SQL

To use or practice SQL, installation of a database engine/software is required, some of the popular engines today are MS SQL, Sybase SQL, and Oracle. Of course, you would also need knowledge of how to write and execute the language. Once all of that is in place, usually you have a frontend terminal window to write and execute SQL scripts and interact with information stored in a database. A very simple SQL script looks like this:

SELECT * FROM customers

The above SQL script would be used to retrieve and display all of the information stored within a table called customers within a database.

Where and How Do I Start Learning SQL?

If you are a student you can apply for a college or university course. People who are slightly advanced in age are also able to take courses at a college or university, there are teachers out there holding SQL courses all the time, search Google for SQL courses and you will find some.

If you are unable to enrol into a college or university, you can learn through courses online, there are great websites out there such as Codecademy and Lynda.com which can get you up and running in no time, their courses are of high quality and I highly recommend them. Codecademy does have a short free course that can give you a flavour of how and why SQL is used, in fact I started with that very course a few years back.

You could also check YouTube, tutors are teaching SQL on this platform for free. In previous years YouTube courses were not great but in the last decade they have significantly improved and I am a fan of it.

Another way you could learn is through a job, if the company you work for is involved in using SQL, then you could learn this on the job just as I did. After going through the Codecademy course and having tested my skills in a test environment I became more involved with customer queries that involved SQL. Typically you would start off with running basic select commands and then slowly learn the more complex commands as you progress and gain trust in your company.

Note: Multiple companies such as Sybase or Microsoft publish their own SQL engines which come with their own SQL language, from my experience these organisations have a lot of the same syntax to write up but do vary in some areas. Don't let this put you off as once SQL is learnt, it is fairly easy to switch to a different organization's syntax, you may need to learn a few new things but generally, it is.

What Kind of Jobs Can I Acquire With Knowledge of SQL?

You could become a developer, a QA tester or even a database administrator, all these jobs pay well but require a lot of knowledge of SQL. Search job boards for the word SQL, read some of the job specifications and find what interests you the most.

There are absolutely tonnes of companies which require databases, if you can create or look after a database, employers will likely take you on.

Knowledge of SQL can also help in acquiring your first job in IT, like a 1st line role or junior helpdesk engineer. I worked as a helpdesk engineer a few years back and knowing SQL helped massively when it came to problem-solving.