OData helps you focus on your business logic while building RESTful APIs without having to worry about the approaches to define request and response headers, status codes, HTTP methods, URL conventions, media types, payload formats and query options etc. With the help of that, our friend Russell can find out the first 2 persons in the system who have registered at least one trip that costs more than 3000, and only display their first name and last name
The actual classes that represent records in the database are generated magically at runtime (hurray for scripting languages) and the files that define the classes only really contain information about relationships between different tables and other code that cant be generated on the fly by accepting the default implementation for everything. This flexible design is really convenient, but comes at the cost of not having straightforward SQL access (sorting, and filtering) to the contents of the field
You select this project template from the Visual Studio New Project dialog box, as shown in the following figure: (Click to view full-size image) When you create an Empty ASP.NET Web Application, Visual Studio creates the following folder layout: This is similar to the Empty Web Site layout from earlier versions of ASP.NET, with one exception. In an enterprise environment, in addition to deploying the Web application files, administrators frequently must modify ASP.NET configuration files and IIS settings
To make the filtering dynamic we will build expression trees that will convert each property to a string, convert the string to lower case, then execute a Contains method against the value of that property. The expression trees implementation is used so that you can apply the solution to any type of IQueryable without knowing what the needing to know the particulars of your object
Just run it by VS2008 Express i had all examples by different implementation of linq, like: - Linq To Sql - Linq to XML - Linq over DataSet - XQury use cases Great! LukCAD - Tuesday, January 8, 2008 7:46:45 AM Great! So why is this a zip somewhere on MSDN that has a code file we need to compile? If this works as good as you say it does, please consider putting it in the Extensions release. Dave - Sunday, February 3, 2008 1:12:49 PM How can you handle null values with the LINQ data source control? For example I have a drop down list that controls the data displayed in a gridview
Introduction To LINQ
As an example, let's imagine we need to get a list of all the svchost.exe processes running on a machine and return them sorted according to their working set. The deep integration of LINQ into .NET languages and tools allows developers to be more productive and work at a higher level of abstraction when creating data oriented applications
If you have not read the previous posts you probably have a life beyond the keyboard, but if you don't then follow the link below to find oodles more to help fill your meaningless existence. This is an expression evaluated against the server's state and can be used to implement optimistic concurrency by basically checking to see if the server's state is still the same as you remembered it
Lucky for us, the query above is really just syntactic sugar and the System.Linq namespace provides us with everything we need to concoct our own lambdas at runtime
Manipulate your expression trees with elegance - CodeProject
The result is an expression tree, which is used to replace the delegate call - and if it has parameters (one in our scenario), they are replaced with sub-trees originally passed to the delegate call (P1, P2, etc. Especially the possibility to build them using lambda expressions keeps your code type-safe, clear and clean and the references inside code are preserved
The Weekly Source Code 48 - DynamicQueryable makes custom LINQ expressions easier - Scott Hanselman
But what price my immortal soul? Fortunately, Marcin from the ASP.NET team decided to come out of his apparent blogging vow of silence (lasting 18 months, no less) to save me. (Is that a word?) Yes, it is :)Wednesday, 27 January 2010 12:15:50 UTCI thought one of the design goals of Linq was to actually get rid of mixing code and the string-based language which is SQL
Extensible Markup Language (XML) 1.0 (Fifth Edition)
All internal parameter entities are well-formed by definition.A consequence of well-formedness in general entities is that the logical and physical structures in an XML document are properly nested; no start-tag, end-tag, empty-element tag, element, comment, processing instruction, character reference, or entity reference can begin in one entity and end in another. By construction, XML documents are conforming SGML documents.XML documents are made up of storage units called entities, which contain either parsed or unparsed data
Database Discussion Boards - CodeProject
Depending on your budget splashing out an a decent SAN solution may help - although SAN technology is beyond my current level of experience, I am just someone who uses it while other people configure it. I think many people still forget that computers have moving parts, they are machines - they are not some sort of quantum flux probability engine that returns results at the speed of light
The anonymous function does not have any intrinsic type associated with it, although implicit conversion is possible for any delegate type as long as the parameters and return type are compatible. The exception to the parenthesis rule is that if the compiler can infer the data type and there is only a single input parameter, the statement lambda does not require parentheses (see Listing 12.17)
I scratched my head a bit and then remembered a long-lost sample for dynamically building LINQ queries written back when the original Visual Studio 2008 shipped. Scott provides a nice overview of the Dynamic Data architecture and then gets his hands dirty with some custom filters using the advanced capabilities available in Dynamic Data Futures
Given this code, the library function calls (like Where and Select in case of LINQ) can consume that expression tree to analyze the code the user wrote, extracting the intent and turning it into execution in whatever way is right for the task at hand (e.g. Typical sample is the use of expression trees in LINQ where nonsense queries can be written, in a sense they cannot be remoted to the target query language
Duncan Ady Admin 565 posts Posted 13 Sep 2011 Link to this post Hello Duncan, It seems that like u.UserGroups is a single object and the from clause expects a sequence of objects
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