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
one time home cleaning Highland Park ..I'm a freelance programmer and somehow I managed to get... Read More
How popular is online shopping? And is there room for... Read More
When people think about the Internet, they think about technology.... Read More
This simple question can take on several different forms, but... Read More
One of my most salient memories from when I sold... Read More
It never ceases to amaze me how many people set-up... Read More
More and more non-profit organizations are developing websites to help... Read More
With search engines putting a damper on direct reciprocal links,... Read More
Keywords in Search Engine Optimizing and Search Engine Marketing are... Read More
We all start out the same. Some have budgets, some... Read More
Writing for the web is totally different to writing for... Read More
cPanel is a control panel for your website and allows... Read More
If you've been developing websites on Mars for the past... Read More
Never has competition been so difficult in the Internet world.... Read More
Before you set up any scripts you will need some... Read More
One of the things that Internet excels is disseminating information... Read More
Every good Internet business understands the value of conversions versus... Read More
"I don't sell anything online, I don't advertise online, in... Read More
1) A marketing necessityI still hear it said from time... Read More
Making maximum profit from your law firm website is important,... Read More
Do you need a web site? Are you considering getting... Read More
I had a client say something to me the other... Read More
When I set up my website I felt paypal was... 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
licensed cleaning services Park Ridge ..There have been many significant changes to the face of... Read More
In about the Time it takes to Watch a Reality... Read More
Through the explosive growth of the Web, companies have realized... Read More
When a user signs up at your website, you may... Read More
1. Address your targeted audience on your business site. Example:... Read More
If you ever want to create a state directory, article... Read More
"I am a writer, not a business-person. I don't want... Read More
The following is a list of patterns that many visitors... Read More
In the late 1990's three San Francisco based web developers... Read More
As increasing numbers of people search for information on the... Read More
How many Web Sites did you stumble over telling you... Read More
There is an ongoing debate about web copy. Some say... Read More
I am just a learner who likes to delve in... Read More
Keywords in Search Engine Optimizing and Search Engine Marketing are... Read More
A lot has changed in the way sites are optimized... Read More
Are bloated images slowing down your web site and causing... Read More
Writing for the web is totally different to writing for... Read More
I still remember it very clear ... It was almost... Read More
A website is like an information flow, with you as... Read More
A while ago one of my clients approached me and... Read More
We are clearly well past the innocent "golden age" of... Read More
Revenues are often lost because many business owners don't see... Read More
Creatively marketing your corporate site takes time in the set... Read More
After years of working with entrepreneurs who developed their first... Read More
Mini Websites are the most powerful and cost effective solution... Read More
Web Development |