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.
personalized cleaning services Des Plaines .."Aaaaaahhhhhh! I've been invaded by a virus!" Getting a virus... Read More
When I first started studying for my CCNP, some of... Read More
Feeling overwhelmed in selecting a new TV? With all the... Read More
Although there are many things that can affect the performance... Read More
We have just entered the time of year that most... Read More
ASR (Automated System Recovery) is a feature available on the... Read More
You???ve studied hard; you???ve practiced your configurations; you???ve used your... Read More
iPod users start to get the picture and it's turning... Read More
All of us are familiar with the pyramids of Egypt.... Read More
Passwords have a strange dual nature. The stronger and safer... Read More
So I'll start from the very beginning.One day I was... Read More
First things first, what is Firefox? Well, it's a browser.... Read More
Apache, MysQL and PHP for Windows could be a nice... Read More
Maybe you always wanted a feature that hasn't been available... Read More
Cookies, not the kind that Mom makes, but the computer... Read More
We've all seen them, you've been browsing a website and... Read More
I have a p3 500MHz PC with 128MB RAM, 10.2... Read More
Lost & Found for the 21st CenturyIn today's hectic world... Read More
I'm eighty-one years old and I bought my first computer... Read More
Cameras: still known for taking pictures but assumed as digital... Read More
PDA Medical BenefitsIf you are concerned about your medical history,... Read More
If you don't have an mp3 player, and even if... Read More
Digital cameras ratings are great tools for deciding which camera... Read More
World War II - Germany decided to attack Poland. Poland... Read More
Yes, it's true. You may have inadvertently invited a spy... Read More
family-safe home cleaners Arlington Heights ..Plenty! When we made the decision to be our own... Read More
So you got yourself a digital camcorder. If you want... Read More
On 21 August 2003 Symantec Security Response upgraded the W32.SOBIG.F... Read More
After another security hole recently surfaced in Microsoft's Windows operating... Read More
Below you will find some useful information and comments about... Read More
Computers have replaced typewriters, but two-finger, hunt-and-peck typing can never... Read More
Having two operating systems is not as difficult as many... Read More
"Aaaaaahhhhhh! I've been invaded by a virus!" Getting a virus... Read More
How long do you think DVDs have around? 20 years?... Read More
As the Web grows more crowded and just plain "noisy"... Read More
Tip #1 -- Rebates: A rebate is not always a... Read More
World War II - Germany decided to attack Poland. Poland... Read More
How familiar does the following sound? Your computer was working... Read More
Heading off on vacation soon?Then perhaps you're tempted to take... Read More
Not so many years ago, homes across the country watched... Read More
Digital Video Disc or as it is sometimes referred to... Read More
Want to save money while promoting your web-based business? Of... Read More
HTTP ProtocolThe web is run on port 80. You are... Read More
In the first part of this home lab tutorial, CCNA... Read More
You will need the following:1. 1.44MB FDD (floppy)2. NVFLASH utility... Read More
The registry is where the computer stores information about the... Read More
The basic language of the internet is html. If you... Read More
When you turn on your computer, does it act like... Read More
This is not your typical lost data story. I was... Read More
Computers are everywhere, and vary in specification, brands, sizes, shaped,... Read More
Personal Technology |