General discussion of SQL Topics; aimed for the novice-intermediate level Microsoft SQL Server User. Currently focuses on using SQL Server 2005.

Wednesday, February 20, 2008

Getting Started – Transact-SQL (T-SQL)

Overview:

This blog is aimed to help you get started using T-SQL. T-SQL is a syntax used in SQL Server; it generally composes of the majority work that is performed in the SQL database to get the data, store the data and/or work with the data. There are various other aspects of SQL Server that are used to perform many tasks that will be covered in other blogs; you'll find that in fact many of the tools used to setup new databases, new users, and other operations/tasks within SQL Server are nothing more than a nice Graphical User Interface (GUI) based on T-SQL commands.

What is T-SQL?

T-SQL, as already mentioned, is the syntax you will use to directly interact with the data stored within your database. T-SQL is typically entered via a GUI tool or application. A typical Database Administrator (DBA) might use Microsoft's SQL Server Management Studio (SSMS) or Enterprise Manager (EM) to enter T-SQL statements. A typical Database Programmer (DBP) might use a programming language such as Visual Basic or C# to enter T-SQL statements.

A common T-SQL statement used, almost in every instance of obtaining data information, is the "SELECT" statement. This statement can be a simple one or very complex. A typical usage may be:

    SELECT * FROM table1

This example would select all data from all columns from a table called "table1". This would be the simplest of all possible examples; but you aren't limited to only this single use. You can create complex SELECT statements that can calculate multiple fields and return the results, could join multiple tables, you could even join tables (or columns) from other databases!

How Do I use T-SQL?

T-SQL is used by entering a line of text within the chosen editor and then executing the command(s) within the SQL Server environment. A DBA may use SSMS to directly enter the commands within the SQL Server environment, or he/she may create a series of commands stored within a file (this is commonly referred to as a 'script') that can later be executed, or he/she may create a stored procedure that holds these commands within the SQL Server environment that can be later called by utilizing the "EXECUTE" keyword.

The important thing to know isn't how to use T-SQL; it's how to find the information to learn how to do what you want with T-SQL. I could spend this whole blog, and many more, on just how to use the SELECT statement; I could spend a lifetime blogging on how to use every T-SQL command there is within SQL Server (and before I even could get through half those commands and new version of SQL Server would appear causing us to restart the learning process!). As the famous saying goes: "Give a person a fish and they eat for a day; teach the person to fish and they eat for the rest of their lives". SQL Server is no different. So, I'm going to concentrate on how to find the information you need.

Where do I find the information I need?

This is actually quite simple to answer…the internet! But, if you want really detailed information that provides you with ALL of the information on how to use ANY (and all) T-SQL commands there is only one place you can go. NO, not this blog…you'd go straight to the horse's mouth; MSDN website. In particular you go to: Transact-SQL Reference (this URL is listed in the "Additional References" section at the end of this blog). This is the pillar to the T-SQL commands; everything starts there! When you first go there you are welcomed with a small page telling you what Transact-SQL is and how it is used; but, that's not the great part yet. The great part is (at the time of this blog) that to the left is a pane (navigation listing) that will list ALL of the T-SQL commands. You can even access other SQL Server reference information from here!

You'll also find many other additional resources on the internet. Microsoft contains a section called "Community" this will provide links to their forums, newsgroups and other websites; I highly recommend reviewing this section and discovering what is contained within these links. Outside of Microsoft there are many, many, hundreds of thousands of websites that cover SQL Server, T-SQL and/or anything to do with databases.

My favorite sites can be found in the "Resources" section of the main page of my blog; this doesn't mean I endorse or agree with these sites…I find that I frequent these sites on an almost daily basis. This listing may change and you are welcome to check back periodically. I also welcome any other suggestions of websites that you may find you can't live without..Please leave a comment to this posting and I'll be sure to make it available to all of the readers.

What books, training or other materials do you suggest?

Well, that is very objectionable. There seems to be no one book that covers all topics; most books targeted at beginner/intermediate users will focus on most popular areas of SQL Server and a good book will make you aware of other areas that exist but are not covered by that book. In regards to T-SQL in particular, I'd recommend for the beginning user to get a book such as SAMS 'Teach yourself Microsoft SQL Server T-SQL in 10 minutes'; this covers the most commonly used T-SQL commands and leads you progressively with each lesson.

I, personally, enjoy the Microsoft Press series for detailed information if I know a particular subject I want to learn about. I also have found that SAMS has other titles that cover a large spectrum of topics and are usually worth looking into.

It all comes down to taste, objective and personal preference. I still, without any doubt, always recommend keeping Books Online handy and using the MSDN website; you'll find most of the answers right there already; the answers you don't find can usually be asked (and receive quick responses) in the forums within the MSDN website.

Conclusion:

There is no single source of reference or answer for SQL Server; you will find that Microsoft has gone to great lengths to provide you with the knowledge and means to gain the knowledge to use SQL Server. If you find that Microsoft doesn't offer what you need then there are many other sites readily available to provide you with that information. Learning is everything!

Additional References

Transact-SQL Reference: http://msdn2.microsoft.com/en-us/library/ms189826.aspx

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