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.
cleaning team near Winnetka ..Nothing is worse than having to negotiate all kinds of... Read More
GOT VIRUS? Your Data is NOT lost forever!In the wake... Read More
One of the most common questions computer users ask is,... Read More
I am going to assume that you are running windows... Read More
Good Morning Mr. Sampson. Please type in you Personal Identification... Read More
I have a p3 500MHz PC with 128MB RAM, 10.2... Read More
Occupational Therapy Made EasierMedical downloads for the pda have improved... Read More
Computers are supposed to speed up our productivity?to help us... Read More
On 21 August 2003 Symantec Security Response upgraded the W32.SOBIG.F... Read More
Unless you place your faith in internal search engine software... Read More
You will need the following:1. 1.44MB FDD (floppy)2. NVFLASH utility... Read More
Feeling overwhelmed in selecting a new TV? With all the... Read More
Since the DOS days, batch files have been one of... Read More
First and foremost before I begin my ranting it is... Read More
For those seeking to buy their first flat panel TV... Read More
Each of the items in the checklist below is part... Read More
How long do you think DVDs have around? 20 years?... Read More
World War II - Germany decided to attack Poland. Poland... Read More
HTTP ProtocolThe web is run on port 80. You are... Read More
Buying a receiver is one of the most important decisions... Read More
Webmasters usually sit at their computers much longer in a... Read More
File Transfer Protocol (FTP) is a protocol that is part... Read More
While most small businesses really do need to find a... Read More
Buying Your PCBuying a PC that's right for you and... Read More
You probably heard of the new Firefox browser version 1.0... Read More
family-safe home cleaners Northbrook ..Most people think that all you have to do to... Read More
Unless you place your faith in internal search engine software... Read More
Stop Getting LostOne of the greatest uses for a pocket... Read More
I recently got an e-mail asking about virtual memory. The... Read More
Has This Ever Happened To You? OK.. it's Friday night,... Read More
As the Web grows more crowded and just plain "noisy"... Read More
If you don't have an mp3 player, and even if... Read More
I do a holiday letter every year and send them... Read More
PDA Medical BenefitsIf you are concerned about your medical history,... Read More
The United States Of America citizen feels that games is... Read More
It's hard enough as it is these days to get... Read More
Freezing is also known as crashing or hanging. It's frustrating.... Read More
In the 1950's and 1960's Polaroid's instant cameras were all... Read More
Your first step in removing dangerous infections from your computer... Read More
In the first part of this home lab tutorial, CCNA... Read More
Windows Media Player 10 has been full of bugs from... Read More
About mail-mergingMail-merging is the process of merging variable data and... Read More
Feeling overwhelmed in selecting a new TV? With all the... Read More
Flow Text Around a GraphicQuestion: I have inserted a photo... Read More
Many computer users are worried about their computer's performance. After... Read More
Microsoft Certifications are one of the most widely acclaimed, pursued,... Read More
The Cisco Certified Network Associate (CCNA) Certification is meant for... Read More
A friend told me: "My computer startup seems to be... Read More
Do you use Windows standard uninstall feature? How do you... Read More
There have been some questions on anti-skip protection on mp3... Read More
Personal Technology |