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 - http://www.sqlprimer.com.
Optimize your time. How much time each day must you... Read More
Looks like every client wants a Flash site these days... Read More
Every small business owner knows that they need a website,... Read More
Every online entrepreneur I talk to is asking the same... Read More
Below, I have listed 8 simple steps that you can... Read More
Part of the success of most home-based businesses is their... Read More
1. Upload robots.txt file in to your root directory and... Read More
You've decided to create a website to market your products... Read More
Everyone wants one.Everyone wishes they knew how to make one.SOME... Read More
Better Web Site ROIHow to increase your business profitability by... Read More
So you finally decided to invest in a web presence... Read More
Selecting the Perfect Domain NameThe first issue I have with... Read More
In the big, wide online world there are millions of... Read More
After years of working with entrepreneurs who developed their first... Read More
Getting a Targeted Visitor to a website is a waste... Read More
If your company own one or more stores, you might... Read More
If you're anything like most small business owners, you probably... Read More
Go to any internet marketing forum you want these days... Read More
Making money with your web site is the dream and... Read More
The Disability Discrimination Act says that websites must be made... Read More
Let's begin by setting some limits. If you're like me,... Read More
A while ago one of my clients approached me and... Read More
One of the biggest mistakes that most online retailers make... Read More
I am just a learner who likes to delve in... Read More
If you are living in a country that its native... Read More
The "robots" meta tag, when used properly, will tell the... Read More
Even with the steady growth of the World Wide Web,... Read More
Psychology is a long word which everyone thinks, "no, that's... Read More
After having decided to start a business, the next thing... Read More
Are you aware that 90% of the websites on the... Read More
When you take a look at the most visited sites... Read More
I'm one of those people that always wanted a website,... Read More
For years now I've been looking to start my own... Read More
Any new website competing on the internet, needs to take... Read More
Having an eye catching website is great, but are you... Read More
Q. Hey, Cathy: I'm just setting up a website. What... Read More
If you don't have a web site yet, are thinking... Read More
The first thing my business consultant (read brother-in-law) asked me,... Read More
When you publish a content site there are times when... Read More
Internet has opened a whole new world for web developers... Read More
Are you aware that 90% of the websites on the... Read More
Many small companies choose not to invest in a professionally... Read More
So you finally decided to invest in a web presence... Read More
Building a website and getting it online is easy. Driving... Read More
August 8 2005, Macromedia announced a release of Studio 8.... Read More
Selecting the Perfect Domain NameThe first issue I have with... Read More
Are you, like many other website owners, frustrated at the... Read More
Looks like every client wants a Flash site these days... Read More
In this day and age most businesses consider having their... Read More
In about the Time it takes to Watch a Reality... Read More
The "robots" meta tag, when used properly, will tell the... Read More
What happened on your website yesterday? What about last week... Read More
Many millions of dollars are being wasted on promoting and... Read More
Like any area of business your website needs some effort... Read More
SummaryHere's the scoop on what you must know when designing... Read More
Starting an internet business can be confusing to non-veterans. The... Read More
While most marketers are beginning to understand the critical importance... Read More
Do you need a web site? Are you considering getting... Read More
Dynamically Update Your Web Pages Via E-MailIf you can Send... Read More
Building a new website can be a lengthy task. From... Read More
You have seen those web pages where they have the... Read More
Launching a new small business website is often a long... Read More
There's been widespread speculation about the new legislation being introduced... Read More
How do you decide on the content, products and or... Read More
You don't believe in astrology but you check your horoscope... Read More
Here's something you may never have thought of before:If I... Read More
Web Development |