Friday, December 4, 2009

What is a Database?

A database is a collection of data.
A database could be as simple as a text file with a list of names. Or it could be as complex as a large, relational database management system, complete with in-built tools to help you maintain the data.
Before we get into dedicated database management systems, let's start with the basics - let's look at a simple text file example. Or it may have rows and columns facility like in spreadsheet. Or it may have functionality like those of MS Access sheet which may have function like auto-increment of the number in the record.

So What's the Difference?

You may be wondering what the difference is between Excel vs Access. After all, both examples have the data organized into rows and columns.
There are many differences between spreadsheet software and database software. The rest of this tutorial will show you why database software is a much better option for creating databases.

Now consider a simple database:


Each row above represents record and each column represents
Record - Each record represents unique item in database.
Field - Each FIELD represents a unique piece of information about the record.

What's SQL ?
In 1971, IBM researchers created a simple non-procedural language called Structured English Query Language. or SEQUEL. This was based on Dr. Edgar F. (Ted) Codd's design of a relational model for data storage where he described a universal programming language for accessing databases.
In the late 80's ANSI and ISO (these are two organizations dealing with standards for a wide variety of things) came out with a standardized version called Structured Query Language or SQL. SQL is prounced as 'Sequel'. There have been several versions of SQL and the latest one is SQL-99. Though SQL-92 is the current universally adopted standard.
SQL is the language used to query all databases. It's simple to learn and appears to do very little but is the heart of a successful database application. Understanding SQL and using it efficiently is highly imperative in designing an efficient database application. The better your understanding of SQL the more versatile you'll be in getting information out of databases.


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