How to Use SQLXML to Retrieve Data from SQL Server Database?

Using SQL Server 2000 and above versions you can retrieve data from SQL Server in XML format directly from the database. Many XML related features were incorporated in the SQL Server database. This enables the development of XML enabled applications very easy and it makes exchange of data over internet easy. In this article we will discuss about how to use SQLXML to retrieve data directly from SQL server database in XML format.

There are some SQL commands and clauses that help you to retrieve data from the SQL Server in the XML format. Syntax for such is given below:

SELECT ... FOR XML mode [, XMLDATA] [, ELEMENTS] [, BINARY BASE64]

There are different modes and that take the values of

· AUTO ? In this mode every row of the result of the query forms an element in the returned XML document.

· EXPLICIT ? This mode defines how to map the columns of the results returned by the query to the XML elements and the attributes.

· RAW - All the fields of the result are identified as attributes of an element.

· NESTED ? The result of this mode is the same as the AUTO mode but the formatting has to be done at the client side.

A simple example of using the above syntax is given below:

SELECT TOP 3 * FROM (SELECT FirstName+' '+LastName as Name FROM Employees) FOR XML AUTO

The query produces this result:

Employees Name="John Peter"
Employees Name="Andrew Dixon"
Employees Name="Tom Hanks"

There are optional parameters in the 'FOR XML mode' clause. The XMLDATA option adds an XSD schema which describes the XML format of the result returned. The ELEMENTS options make the fields of the tables in the database to be returned as child elements. If the ELEMENTS option is not there the fields of the tables are returned as attributes instead of child elements of the XML document. The ELEMENTS option is allowed only in the AUTO mode. The BINARY BASE64 option is used to retrieve any binary data. The returned binary data is returned in BASE64 encoded format. The binary data can be retrieved in the RAW or EXPLICIT mode.

An example of the RAW mode is given below:

SELECT EmpName, EmpCity from EMP for XML RAW

The above code returns a result like,

row EmpName="John" EmpCity="New York"

In the above result you can note that the fields of the resultset are returned as attributes of the element.

.Net provides with managed classes for interacting with SQL Server. The managed classes of SQLXML provided by .Net are:

· SqlXmlCommand ? This is used to perform queries that are stored in XML documents which are also called XML templates. This class also provides support for client side XML processing.

· SqlXmlParameter ? this is used to provide parameterized values and is used along with SqlXmlCommand object.

· SqlXmlAdapter ? this is the adapter class for SQLXML provider. This is used to fill the dataset.

· SqlXmlException ? this is used to trap the error information from the SQL Server.

A sample code using the managed classes is given below. For detailed information on the usage of the above managed classes you can refer to the MSDN documentation.

static string cstr = "Provider=SQLOLEDB;Server=(local);database=EmpPersonal;"; public static void testingSqlXml () {

Stream oStr = Console.OpenStandardOutput();

SqlXmlCommand sqlcmd = new SqlXmlCommand(cstr);

sqlcmd.Root = "Employees";

sqlcmd.CommandType = SqlXmlCommandType.Sql;

sqlcmd.CommandText = "SELECT EmpName, EmpCity FROM Employees FOR XML AUTO";

strm = sqlcmd.ExecuteToStream(oStr);

oStr.Close(); }

Thus we have seen that SQLXML can be used to retrieve data directly from the SQL Server in XML format. It is easy to handle and transmit data through the internet if it is in the XML format and this can be easily achieved using the SQLXML.

Want to stay current with the latest technology developments realted to XML. Visit Free XML Tutorial to get your FREE subscription now!

** Attention Webmasters / Website Owners ** You can reprint this article on your website as long as you do not modify any of the content, and include our resource box as listed above with all links intact and hyperlinked properly.

Basic Diagnosis Guidelines for Your PC

Simone is exasperated. She has to work on her university... Read More

Windows PDA Medical Software Benefits

PDA Medical BenefitsIf you are concerned about your medical history,... Read More

Taking Advantage of the iPod Experience

Music lovers have been carrying around radios and other bulky... Read More

Cisco CCNA Certification: Five Things To Do DURING The Exam

There are plenty of articles out there about how to... Read More

Why Build Your Own Gaming Computer?

The best way to get the gaming computer that you... Read More

How Do MP3 Players Work? Digital Audio Technology Revolutionizes Music Enjoyment

Millions have enjoyed recorded music since 1877 when Thomas Edison... Read More

Are You Putting Off Productivity?

I recently took a good look at what was keeping... Read More

Make Windows XP Run Faster!

A friend told me: "My computer startup seems to be... Read More

5 Steps to Remove Spyware for Free

Have you ever tried to remove Spyware off your PC... Read More

Does Microsoft Show Hackers How To Attack?

After another security hole recently surfaced in Microsoft's Windows operating... Read More

Registry Tools Demystified

Not sure what Windows registry is or how it works?... Read More

Selecting a Personal Digital Assistant

A Computer in Your HandCarrying around an address book and... Read More

Learning To Navigate Ciscos Online Documentation

When studying for your Cisco CCNA, CCNP, or CCIE exam,... Read More

10 Time Saving Keyboard Shortcuts

Time is money. And when you constantly have to divide... Read More

Refurbished Computers on the Internet

What is a Refurbished Computer?Refurbished Computers. Remanufactured Computers. Reconditioned Computers.... Read More

The Newbies Guide to Personal Computer Maintenance

When you turn on your computer, does it act like... Read More

Reliable File and Folder Sharing in Windows Xp

This tip is on sharing files and folders on a... Read More

SOBIG.F Virus Promises Ill Be Back

On 21 August 2003 Symantec Security Response upgraded the W32.SOBIG.F... Read More

Cisco CCNA / CCNP Certification: OSPF ASBRs Explained And Illustrated

When I first started studying for my CCNP, some of... Read More

D2X Digital SLRCoolpix 8800 Actually Refers to Two Nikon Cameras

Addressing a D2X Digital SLRCoolpix 8800 search, this article provides... Read More

Temporary Fixes to Spyware, Ad-ware, and Virus Infections

So you've got some spyware, ad-ware, or viruses on your... Read More

Be Your Own IT Department

If you use a computer, you need to know more... Read More

Flow Text Around a Graphic in Microsoft Word

Flow Text Around a GraphicQuestion: I have inserted a photo... Read More

Is Online DVD Rental or Pay-Per-View the Best Way to Get Your Movies?

With renting methods such as online DVD rental and pay-per-view,... Read More

Portable DVD Players - Things To Know

In my humble opinion nothing makes a long trip easier... Read More