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.
family-safe home cleaners Lincolnshire ..Cisco Certification: Taking Your First Certification ExamYou've studied hard; you've... Read More
Everywhere you look today people are listening to personal audio... Read More
Want to save money while promoting your web-based business? Of... Read More
Has This Ever Happened To You? OK.. it's Friday night,... Read More
Do you know how many fonts are currently installed on... Read More
In the first part of this home lab tutorial, CCNA... Read More
By using your computer today you can find a lot... Read More
Spyware is the software that collects information about your online... Read More
Stimulus thru Caffiene or Visual Input?It appears that the Mobi... Read More
Music lovers have been carrying around radios and other bulky... Read More
Have you ever tried to remove Spyware off your PC... Read More
Webmasters usually sit at their computers much longer in a... Read More
Computer is an electronic machine work on the instructions of... Read More
I've worked my way from the CCNA to the CCIE,... Read More
First and foremost before I begin my ranting it is... Read More
I'm eighty-one years old and I bought my first computer... Read More
Choose Not To ConformPalm pilots and pdas are constantly growing... Read More
Nothing is worse than having to negotiate all kinds of... Read More
This tip is on sharing files and folders on a... Read More
You will need the following:1. 1.44MB FDD (floppy)2. NVFLASH utility... Read More
Flow Text Around a GraphicQuestion: I have inserted a photo... Read More
ASR (Automated System Recovery) is a feature available on the... Read More
As the Web grows more crowded and just plain "noisy"... Read More
Projectors have come a long way in the past few... Read More
GOT VIRUS? Your Data is NOT lost forever!In the wake... Read More
maide service in Buffalo Grove ..Feeling overwhelmed in selecting a new TV? With all the... Read More
I have a love-hate relationship with my computer.In fact, often... Read More
If you're like me, you occasionally find the ubiquitous mouse... Read More
You???ve studied hard; you???ve practiced your configurations; you???ve used your... Read More
You will need the following:1. 1.44MB FDD (floppy)2. NVFLASH utility... Read More
The technological horizon has always got something new to offer,... Read More
Not sure what Windows registry is or how it works?... Read More
That desk in front of you and everything else around... Read More
Digital Video Disc or as it is sometimes referred to... Read More
Your Bible At Your FingertipsIt is fairly easy to find... Read More
Maintaining your computer is extremely important ? especially if you... Read More
Getting a new computer should be an exciting and gratifying... Read More
I've worked my way from the CCNA to the CCIE,... Read More
Get started creating web pages using text files and HTML... Read More
Those small USB drives have so many names, pocket drives,... Read More
First things first, what is Firefox? Well, it's a browser.... Read More
Are you stymied by the vast offerings in cheap mp3... Read More
Windows Media Player 10 has been full of bugs from... Read More
How long do you think DVDs have around? 20 years?... Read More
Digital cameras ratings are great tools for deciding which camera... Read More
One of the most confusing parts of beginning your Cisco... Read More
Viruses, software failures, power failures, human errors, hard drive failures... Read More
JPEG, GIFF/JIFF, BMP, and TIFF are the most commonly used... Read More
ASR (Automated System Recovery) is a feature available on the... Read More
Are you looking for an MP3 player but am not... Read More
Personal Technology |