In this post, you learn how to create an xml file by using linq. Whether xml is being queried, parsed, or transformed, linq to xml can almost always be used as an easier alternative to previous technologies that are based on xmlspecific languages xpath, xquery, xslt. Text content is released under creative commons bysa. It eliminates the need for a developer to learn the xml query language which is somwhat complex. Linq to xml offers easy accessibility to all linq functionalities like standard query operators, programming interface, etc. Linq to entities query creation and execution process. Net support for todays restful web services and web api. This paper mainly focuses on specification of linq components utilization and main. Pdf linq which is the abbreviation of language integrated query substantially.
By including an xml schema document, linq to xsd will code generate strongly typed wrapper classes, permitting you to read and write the xml document as easily as you would create and use any objects. Linqtoxml node creation, simply said, is the natural way to create nodes with code that is structurally identical to resultant xml. In this article, we will see basic things on how to work with xml using linq, where we will deal with storing and reading server information in xml format. I would instead create each new document, including the address, then add that to documents. The acronym linq stands for language integrated query. And last i want to add another sql statement in the string select from employees where city london it will show these result in the same xml file at bottom. Create an xml document with linq to xml intertech blog. Linq creates report class based on the database table called dbo. In this update, youll discover the tight integration of xml with ado. It is also possible to save xml documents existing in memory to disk and to serialize them. Or you can declare in advance, a class with members and create object of that class. Net framework functionalities like debugging, compiletime checking, strong typing and. Some of the major topics we cover include creating xml documents and xml schemas, free tools to validate xml and generate xml schemas, use linq to process xml documents, joining xml documents together to create a new xml document, aggregating data using builtin methods and functions, learn to use xpath queries, add, edit, and delete nodes in.
Net framework that encompass languageintegrated query, set, and transform operations. No part of this document may be reproduced or transmitted in any form or by any means, electronic or mechanical, for any. Shows how to use the let clause to calculate intermediate values in a linq to xml query. Linqtoxml node creation, simply said, is the natural way to create nodes with code structurally identical to resultant xml.
Today xml is generally used to store data and transport it on the web. See credits at the end of this book whom contributed to the various chapters. Introduction of linq to xml while using linq to xml, loading xml documents into memory is easy and more easier is quering and document modification. Create xml from database using linq dot net tricks. The below lines of code explains the usage of linq and also the advantages of using linq compared to a legacy approach. The following example creates an xdocument, saves the document to a stringwriter, and then prints the string to the console. Create xml using linq to xml functional construction is the simplest linq to xml approach that is used to create a xml file. The signatures of the xelement and xattribute constructors let you pass the contents of the element or attribute as arguments to the constructor. Advantages of linq linq offers a host of advantages and among them the foremost is its powerful. Create new xml documents using the classes provided by. Linq, the same data query can be written in a readable colorcoded form like the following one mentioned below that too in a very less time. When my current project started in 2007, linq was just starting out and i wanted to stay with the famliar to generate the xml document so i used the system. Hi, how can i take the results of a linq query and convert to xml and save to file. Programming with linq to xml for objects linq to xsd.
Linq xml linq to xml offers easy accessibility to all linq functionalities like. The ienumerable interface has a single method, getenumerator, which returns an ienumerator while the yield keyword can be used to directly create an ienumerable, it can also be used in exactly the same way to create an ienumerator. Like i want to run this getemployeesstring country then it run my following code and generate the xml file. Linq namespace, this class is inherit by xcontainer class.
On above code, we have used the simplified dynamic object approach. Thats one of the benefits of linq to xml, that it makes life easier for developers by making it so easy to create and structure xml documents. An attribute of the element can be defined by using the xattribute class. This can be useful if we want to create our own class which implements. Its also worth observing that the structure of the code shown below is similar to the structure of the end result xml document. Conversion of standard query operators of linq as well as linq expressions into command trees. Linq to xml provides an inmemory xml programming interface that. The xdocument s root property returns an xelement representing the root element of the xml file. I have tried and achieved 95% only a smail issue remains.
Linq is a readable code that can be used as a standard way to extract data from xml documents, arrays, relational databases, and other thirdparty data sources. Net have been around for a very long time, but their constant growth means theres always more to learn. Writexml, but my concern it is so easy to create the xml document by using the linq to xml. Linq to xsd is an extension of the core linq technologies and is at present still in alpha.
In the example code below, data source is a collection of few books stored in an array called book. Icloneable xml nodes can be copied to create a new instance. To save it, you could use serialization in my option, easyly to do or xmldocument and xmlwriter to do fine but dificult to do. The code is shared below the legacy code has been commented out. Microsofts query language is fully integrated and offers easy data access from inmemory objects, databases, xml documents, and many more. It is creating the xml file but can i formate the xml file. For reference documentation for the extension methods that help you validate xml trees against an xsd file, see system. While you could use linq to xml as little more than a simpler way to create xml documents, you can also. Taking the boredom out of querying joseph albahari. Net framework, linq to xml also makes the best use of. Xml parser that creates such a tree is known as a dom parser. This is a 500 pages concise technical ebook available in pdf, epub ipad, and mobi kindle. For reference documentation for the extension methods that enable you to evaluate xpath queries on an xml tree, see system.
Net language integrated query linq to objects datasets linq to sql linq to entities linq to xml objects relational xml figure 3. An example of this is to transform an object model into an xml document suitable for transmission to a web service. In this approach, the queried results for linq to xml are used in the constructors of xelement and xattribute objects to create and transform the xml trees. I will explain you about to create the xml file using linq to xml. Linq or language integrated query is a part of the microsoft dot net framework which provides easily understandable data querying facilities to. The only thing that changes is the return type of the method. The xmlreadersettings objects has a schemas property that can be used to perform xsd or dtd validation. This modified text is an extract of the original stack overflow documentation created by following contributors and released under cc bysa 3. By using the current apis, it is slightly cumbersome to handle and play with xml data.
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