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SQL by Theinchai Oranrigsupak

What is SQL?

SQL or Structured Query Language is a standard programming language for retrieving information from and updating databases.  SQL enables user to select, insert, update, and delete data from database.  It is a standard language that all commercial databases, such as Oracle, IBMís DB2, Microsoft SQL Server, Microsoft Access, etc., support.  However, most database vendors have also added their own proprietary extensions to the standard SQL.  SQL can also be used in association with programming languages like Visual Basic or Active Server Pages.  For example, you can write a visual basic program or an active server page with SQL component to retrieve data from or update data in databases.

Business uses of SQL

Virtually every company in every industry nowadays has at least one database.  And for every company that has a database, use of SQL is almost inevitable.  There are two layers of business use of SQL.  First, as a user, you can use SQL to manipulate database directly.  For example, a security analyst may use SQL to search for and retrieve financial data form database for analysis.  Secondly, from an application development standpoint, SQL can be used to develop a web page that has capability to interact with database.  This is the technology that most web stores like use to manage their interactive websites that sell stuffs.  And as a consulting firm, we can recommend SQL as a solution to a security company or a newly developed dotcom company, for instance.

Weakness & Strength

One of SQLís weaknesses is the incompatibility due to the fact that different vendors have their own versions of SQL.  An SQL statement written for one vendorís database may not work with another vendorís database.  Another weakness is its text-based interface.  This makes SQL not very user-friendly.  You have to type in all the commands.  So, it may be difficult for a beginner to use.  However, once you learn to use it for a while, it can be a very powerful tool for manipulating database.  And that is its strength.  Some people may argue that they can use a built-in function of database software, such as Accessís QBE (Query By Example), to easily get a search result or to manipulate data.  However, this function is useful only for simple query.  As your solution requires more complex query, SQL has proven to be a more robust tool.  Another strength of SQL is that there is not a lot of syntax to remember.  The main ones are SELECT, FROM, and WHERE.  It is somewhat like natural language.  You just provide what you want to SELECT, FROM which table(s), and with any condition specified after WHERE.  So it may not take long before you are adept at using SQL.

Why learn SQL?

One of my MBA professors said that it is always a good idea for an IT manager or consultant to have a hands-on experience with SQL (as well as with any other Information Technologies).  The first benefit is that you will get a better understanding of SQL and database structure.  You will know the limitation and the possibility of what SQL capabilities.  You will also realize in what situation SQL can be a potential solution to the management problem at hand.  You donít have to master SQL but you should learn it to know at least enough to be able to communicate with developers comfortably.  You can tell them what your ideal solution is.  Another reason is related to one of its business use.  That is, you can retrieve data that you want on your own without having to depend on programmers.  This will save you some times when you need quick result and fast turnaround.  And lastly, as database become ubiquitous, knowing SQL will provide competitive advantage to both you as an individual and our consulting firm.