Virteacon: SQL for Beginners Part-1: Basics

Its the point of time where all students, no matter which stream, get into the IT industry. And with this ever growing competition in the field, it can be really hard for a Non CS student to cope up with the pace. Firms such as TCS have asked to prepare certain topics as a part of Pre-ILP(Initial Learning Program), and certain other firms like Wipro and Infosys provide certain sessions of training. But none of these courses would teach you or make you familiarize about the basics. And one such integral part and language on which the IT industry lives is the SQL(Structured Query Language).
This is a Language you should know, atleast the basics should be familiarized. So let me get to the points straightaway. Hope you still remember the expansion of SQL - do you? Ha, never mind if you don't, it was a really twisted term for me back in the time I began studying it. So for the note , SQL- Structured Query Language. It's a language, and what do you basically use a Language for? To express something. So is it like C/C++ or any other language out there? What do you think? Well, the answer is NO. C/C++, Java etc. are programming languages, meant for Programming, designing and various other stuff. But SQL, is a Query language.

So a new term - Query, Wikipedia defines a Query as "a form of questioning, in a line of inquiry". And that's SQL is all about. It is a line which gives us some information. You can think of an example like this, when you Search something in Google, the Text you enter is actually a query. This query is matched for in the Information base of Google. SQL functionalities are restricted to Queries, accessing and Manipulating the Information Base. So now that you know what a Query is, the next term is a Database.

What is a Database? I'l get back to Wikipedia for the definition, "A database (DB) is an organized collection of data for one or more uses, typically in digital form". Remember I said earlier that Google will check for the query in its Information Base? Any thoughts on what this Information Base is? The whole information base is organised as a Database, the integral part of any Software Project. A Database is basically a set of tables which contain information of the particular project. To get a clear idea on how a database looks, let me take an example. Consider the 'information base'(Hereafter would be mentioned as Database) required to maintain the Students details. The Attributes required for a student would be - Student Name, Roll No., Mark1, Mark2 and Mark3. Note that you have learned a new term here - Attributes. This is how the Database for Student Details would look like.

Remember I mentioned the Column Names as Attributes? Similarly the Rows are called Tuples.

I guess this would be enough for Part 1! Following parts to come soon. Wait! Wondering why you have to know about all these when I put up the Title as SQL? This forms the base, you put the Queries on these databases! Rest in Next!

You learned in this part