What is SQL? SQL stands for Structured Query Language and is the lingua franca in the database world. SQL is a standard that is used by all database vendors and programmers to define, extract and access the information that is stored in databases. SQL began life as an IBM creation but was standardized by the American National Standards Institute (ANSI) and the International Organization for Standardization (ISO) as ANSI/ISO SQL in 1988. Since then ANSI/ISO SQL standard continued to evolve. The ANSI-SQL group has since published three standards over the years:
1. SQL89 (SQL1)
2. SQL92 (SQL2)
3. SQL99 (SQL3)
SQL is a query language. It is English-like and easy to use. However, although there are more than 90 SQL reserved words, most programmers seldom use more than the following handful of commands - SELECT, INSERT, UPDATE, DELETE, FROM, WHERE, HAVING, BETWEEN, LIKE, OR, AND, NOT, IN, ORDER, GROUP and BY.
For example, if you had a database table named "employees" and you wanted to retrieve all records where the employee has the last name "goodman", you would use the following SQL statement:
SELECT * FROM employees WHERE lastname = 'goodman';
There are many different categories of SQL statements but the basic ones which all programmers should be familiar with are the SQL statements that:
1. Create tables and manipulate their definitions
2. Query the table data
3. Manipulate the table data
SQL is predominantly used by 2 types of users - programs and humans (keying in the commands through a database client) - to pass instructions to databases. SQL commands can be keyed into a database client like the MySQL Query Browser or the SQL Server Enterprise Manager and executed to either return a result or modify records in the database. SQL can also be used in conjunction with programming language or scripting language like Microsoft Visual Basic or PHP to communicate with the database.
Although SQL is a world standard, it is unfortunate that most database vendors have come up with different dialects and variations. This is because every database vendor wants to differentiate their database products from the crowd. One good example is Microsoft SQL Server's TRANSACT-SQL. TRANSACT-SQL is a superset of SQL and is designed for use only with Microsoft SQL Server. Although it does make programming much easier for software developers, it is not compliant with other databases like Oracle or MySQL - making TRANSACT-SQL programs non database-portable. As such, although many of these features are powerful and robust, it is good practice to exercise caution and limit your SQL use to be compliant with the ANSI/ISO SQL standards and ODBC-Compliant.
Courtesty of sqlprimer.com. For more information, please contact the Webmaster of SQLPrimer.com - sqlprimer.com
spotless home service Lake Forest ..Making a web site is easy. Making a good web... Read More
Every small business owner knows that they need a website,... Read More
You've just finished congratulating your marketing team. After six months... Read More
After years of working with entrepreneurs who developed their first... Read More
Most people know they need a website in order to... Read More
1) Word of Mouth The single most powerful form of... Read More
Is your website Really useful?I had a 'rep' in yesterday... Read More
Three way linking and concerns.For many years SEO experts were... Read More
Globalize Your WebsiteThe Internet has unlocked a wide array of... Read More
Installment 1Developing State-enabled Applications With PHPWhen a user is browsing... Read More
If you have some experience in web site design and... Read More
For years now I've been looking to start my own... Read More
When you take a look at the most visited sites... Read More
Your content is what gets you in search engines, speaks... Read More
Knowledge is power.And undoubtedly, it is the key to making... Read More
Part of the success of most home-based businesses is their... Read More
A PHP Redirect automatically transfers a web user from one... Read More
Build it and they will come is not always true;... Read More
If you are like me you have wanted to build... Read More
RIVERSIDE, CA August 4, 2004 ?- "Historically, small business owners... Read More
My life's greatest passion is a safari hobby. And what... Read More
There are lots of HTML editors on the market, however,... Read More
It may come as some surprise to a traditionally off-line... Read More
When visitors add your web site to their Favorites or... Read More
Absolutely everything stems from the purpose of your website -... Read More
weekly home cleaning Mundelein ..You work hard to build traffic to your web page.... Read More
To the starting internet entrepreneur, there is nothing more discouraging... Read More
When web content gets discussed on webmaster bulletin boards, the... Read More
Alternate medicine finds its own place in the hearts and... Read More
What is the most important part of your online business?Many... Read More
Appealing to others is really important when you have a... Read More
In a previous ezinearticles.com article,"I Need real visitors, Not Search... Read More
"'Page Not Found' on this Server. Check the URL and... Read More
First, using a lot of web graphics, flash, banners and... Read More
Writing for the web is totally different to writing for... Read More
When visitors add your web site to their Favorites or... Read More
So you have a good idea for a business and... Read More
More and more businesses are recognizing the importance of content... Read More
Anyone who knows anything about web accessibility knows that images... Read More
First, an eye opener. Making your fortune through affiliate programs... Read More
There are lots of HTML editors on the market, however,... Read More
Are you, like many other website owners, frustrated at the... Read More
When you take a look at the most visited sites... Read More
Your content is what gets you in search engines, speaks... Read More
A website is like an information flow, with you as... Read More
If you are looking for creating your online presence you... Read More
One of the things that Internet excels is disseminating information... Read More
It may come as some surprise to a traditionally off-line... Read More
You have permission to publish this article electronically, in print,... Read More
In about the Time it takes to Watch a Reality... Read More
Web Development |