What is SQL?
SQL stands for 'Structured Query Language'

What does that mean?
There are a lot of Databases available in the market such as MS Access, Oracle and many others. For you to write programs that interact with these databases easily, there has to be a way where you could get information from all these databases using the same method. For this purpose SQL was developed. It is a kind of language (simple when compared to the likes of C or C++) which enables you to ask all your queries to a database without bothering about the exact type of database.


What the heck is SQL??!!!
Ok lets get straight to the point. Suppose you have a database which has a table called people. (I hope you know what tables are). And you want the details of all persons whose firstname is 'Reena'. So you could use a SQL statement as follows

SELECT * FROM people WHERE firstname = 'Reena'

When you use this Query the database engine would first find the table called people. Then it would find a column called firstname. Next it would compare all the values in that column with 'Reena'. Finally it would return all the details wherever it finds a match for the firstname.


Tell me something more of the bigger picture..
When you write a database program in VC++ or Java or any other language for that matter, you would make a database connection to your database and then you would query the database using SQL queries. When you query the database with any SQL query the database returns a recordset. A recordset is basically a set of records (all the entries that your query returns). This recordset is received in your program and all languages have a data structure which represents a recordset. Once this data structure (in your program) gets populated with the results from the database query, your could use a for loop to loop through all the entries.

How do I connect to a Database through my program?
Hey guys.. this is a tutorial on SQL.. so I wouldn't be focussing on those aspects in this series


What was that thing about recordsets?
When you connect to a database and execute SQL Queries,the results of the Query are returned back to your program. This returned data has to be stored in some Object or Data Structure within your program to be used by your program. Once you store the results in this Object you no longer have to be connected to the Database. For a more detailed explanation please refer to a book on Database programming.