Create web api controller with read write scaffolding option. If nothing happens, download github desktop and try again. Now i want to look at returning iqueryable from web api methods. Net and for teams that feel repository patterns that expose iqueryable as a leaky abstraction, simple use urfs iquery api, which will give you all the fluent features of iqueryable, however will return pure entity or ienumerable vs. Well go step by step in the form of a tutorial to set up a basic web api project and well use. Net developers have been able to create odata feeds since before there was even an odata spec. Using ef and webapi, how can i return a viewmodel and support iqueryableodata. Add a action in previously created home controller and attach a view. I also use entity framework to store and retrieve data, though that is. Otherwise we can easily install this using the nuget gallery. Net generic queryable repository that can be used in a variety of projects most. Iqueryable basically generates the complete expression tree and then executes it to get results, where are it is not true in ienumerable scenario.
Well go step by step in a form of tutorial to set up basic web api project and well use. Sep 27, 2015 in this video, i will demo how to make searching data in asp. In this section, well add web api controllers that support crud operations create, read, update, and delete. Sep 29, 2014 in this article i will showing a complete walkthrough for creating restfull services using asp. Kendoui grid, odata, webapi and entity framework blog it. Entity framework, it may be better to return iqueryable to leverage features like deferred execution. In the spotlight demystifying iqueryable entity framework 6 published on nov 24. How to use web api odata to build an odata v4 service. We will be using this service as the basis for understanding many of the web api. I have created a controller that is based on apicontroller and i have a method. Jun 25, 2018 in this post, we are going to convert the synchronous code to asynchronous inside asp.
How can i map my entities to a viewmodel automapper. Is using odata\iqueryable in your web api an inherently bad. When you dont have any virtual properties the orm is safe to use an instance of your type. Odata will apply the parameters to any iqueryable and entity framework is in many cases able to create perfectly reasonable, clean and performant sql. Youre all doing entity framework wrong michael hoagland. As part of getting to grips with iqueryable, i downloaded the entity framework source code from codeplex and started examining it. Normally, caching is the process of storing data somewhere for future requests, in our case we can avoid the unwanted hit to database to get the data if we cache the data somewhere, this way we can make sure that the data is served in a faster manner.
Right now, our web api exposes the database entities to the client. Jun 07, 2019 in this post im going to show you how to return an unlimited number of results from a database via a web api application while keeping your memory usage low and constant. I am trying to maximize the efficiency of my web api controllers and have read that using iqueryable provides a benefit in skiptake linq calls by executing the filter on the server, rather than retrieving all records and then performing the filter on the client. Without a shadow of a doubt we get back an iqueryable which is an entity from the entity framework, meaning we use the entity framework inside our applications or services layer. For projects that support packagereference, copy this xml node into the project file to reference the package. But when people talk about odatamvc and the web api then automatically the entity framework is related if the underlying data source is a sql table database.
The client receives data that maps directly to your database tables. Net web api get, post, put, delete using fiddler 100,557 views. However, when you have virtual properties the orm has to use its own type in order to support lazy. Entity framework creating model from existing database and using it in sample. Full northwind sample application angular, web api, odata, entity framework.
You can build and execute queries using entity framework to fetch the data from the underlying database. Net web api and use the entity framework 6 in the application for communicating with the. For the most part it is compatible with the previous queryable support because it supports the same odata query options. This tutorial will teach you the basics of creating a web application with an asp. Net webapi as the interface for accessing the data. If you want a quick try or you have your own way of implementing data sources, these tutorials may not be the best fit. Implement a structure that exposes a stronglytyped filtersortpage api and builds the iqueryable internally. In this post im going to show you how to return an unlimited number of results from a database via a web api application while keeping your memory usage low and constant. This section describes some details of how ef loads related entities, and how to handle circular navigation properties in your model classes. Well use the linq select statement to convert from book entities into dtos. I worked in an extremely small web department so i often had to dive into the database myself to create tables and do tasks. This string points to a property or field name of the entity. Is using odata\iqueryable in your web api an inherently.
Ef 6 supports different types of queries which in turn convert into sql queries for the underlying database. Sep 04, 2016 in this video we will discuss creating asp. Net, entity framework, linq to sql, nhibernate web api model and controller linq join web api model and controller. Autoqueryable and automapper do not work together when it comes to mapping entity relations from an entity to a dto. Entity framework 6 ef6 is a tried and tested objectrelational mapper for. Petapoco does not provide any iqueryable data support, so we changed our orm to entity framework, which does, and voila. Autoqueryable add auto querying functionality like odata on top of iqueryable with best url practices to asp.
Blog last minute gift ideas for the programmer in your life. Browse other questions tagged entity framework web api odata iqueryable or ask your own question. Streaming results from entity framework core and web api. That is a leaky abstraction and a violation of separation of concerns principle.
In the previous article, weve learned the highlevel overview of what entity framework is all about and learned how to build a web application quickly using entity frameworks databasefirst development. In the spotlight demystifying iqueryable entity framework 6. And there is a lot of theory you can read about web api on msdn. This is a follow on from my post on web api and the entity framework. To fix this, use the autoqueryable profile setting profile. In the last article of learning entity framework, we learned about the codefirst approach and codefirst migrations. Generic queryable data repository codeplex archive.
Net webapi 2 and entity framework code first approach for all database related operations. For example, entity framework api implements iqueryable interface to support linq queries with underlaying databases such as ms sql server. The iqueryable interface is used to provide querying capabilities against a specific data source where the type of the data is known. Want to be notified of new releases in mikewassonbookservice. Jun 24, 20 is using odata\iqueryable in your web api an inherently bad thing. Net web api is a framework for building web apis on top of the. Easily enable pagination, ordering and filtersearch on a normal web api controller. I prefer the third though ive helped colleagues implement the second as well, but theres. This overview with code examples demonstrates the supporting odata query options in asp. Net, entity framework, linq to sql, nhibernate group by iqueryable linq group by iqueryable linq answered rss 6 replies. Learning web api 2 with entity framework 6 code first. Creating web api using entity framework with linq query in mvc 4. Odata supports query composition and sqllike parameters.
Learning web api 2 with entity framework 6 code first migrations. Myentity, func dtocreator it implements iqueryable so we still return it allowing webapi to apply any odata but the func gets called once ef completes thus allowing any. Create our easytouse paging method that will magically turn an iqueryable into. This is the active development branch for odata webapi and it is currently. Please read our previous article where we discussed the different ways to write linq queries with examples. In this article i will show that how we can make our web api methods queryable so the. Adds entityframework core iqueryable support to graphql simoncroppgraphql.
This will be part five of a six part series of blog posts. In that post, i showed a couple of approaches to dealing with json serialization problems in the visual studio 11 beta. May 08, 2017 youre all doing entity framework wrong. Net with many years of feature development and stabilization. Jul 01, 2015 i was working on some code that used entity framework and an asp. Net web api service that returns data from a sql server database. Entity framework, while being a solid data access framework is laden with many gotchas that make your application prone to. Is using odata\iqueryable in your web api an inherently bad thing. Expose odata endpoints without entity framework and.
The breezequeryfilterattribute converts breeze client query urls into linq expressions. Net web api 2 with entity framework 6 code first migrations. Net core api controller methods queryable with a single attribute. Introduction in the last article of learning entity framework, we learned about the codefirst approach and codefirst migrations. I say more about navigation properties in part 4, handling entity relations. I tried to include code samples, some best practices and some common pitfalls. Adds entityframework core iqueryable support to graphql stefhgraphql. Web api queryable current support and tentative roadmap.
Net core custom api controller crud operations with ajax calls. I also use entity framework to store and retrieve data, though that is not the focus of this particular. In this article, we are going to discuss the following concepts in detail. First, we are going to learn a bit about asynchronous programming and why should we write async code. Mvc 4, web api, odata, entity framework, kendo ui, binding. Here i am using the last project which i have created in the previous article on how to create web api. Even entity framework has lots of unsupportedexceptions.
Streaming results from entity framework core and web api core. In this article, well learn how to perform crud operations with asp. Code first approach using entity framework core in. The only extension i have needed is include, which i found a workaround for. I guess id need to provide some kind of 2way translation for the query. The breeze getting started tutorial creates a selection of endpoints grouped into a single. Presumably you are retrieving this object using entity framework or a similar orm. Serialise iqueryable collections using odata the asp. Net web api web api crud operations with entity framework. Using automapper to improve performance of entity framework. You can download an example project complete with unit tests. The odata library can use this to determine how to pass the filter on to the entity framework, so that your select is translated into proper sql.
An angularjs client will consume a web api method which will perform database operations using entity framework in asp. In this article we will extend this sample with some additional code. In my previous article available here article i tried to briefly introduce you to entity framework core objectrelational mapper used together with asp. Well go step by step in the form of a tutorial to set up a basic web api project and well use the codefirst approach of entity framework to generate. Mar 30, 2012 mark seemann suggests in his article iqueryable is tight coupling that designing an api such that it exposes an iqueryable interface is a bad idea for several reasons.
Now run and see output of api controlleremployee step 5. I also use entity framework to store and retrieve data, though that is not the focus of this particular project. Poor query performance due to improperly constructed queries. All of your queries for data when using entity framework are written against dbset. In this article, we will are going to learn how we can use caching in web api. Mark seemann suggests in his article iqueryable is tight coupling that designing an api such that it exposes an iqueryable interface is a bad idea for several reasons. This example in particular requires automapper, which will allow us to easily map our entities to our returned api models.
For the user class, we have properties like userid, name, address, contact. I really like using iqueryable to hide the entity framework commands. Microsoft entity framework is an orm objectrelational mapping. Also, there are apis available to access third party data. A roslyn analyzer to check for common gotchas with linq expressions when used with entity framework. Entity framework is an orm technology widely used in the. That said there has been a little confusion about how queryable works, what it. By using wcf data services, you could expose an entity data model edm over the web. Visual studio 2017 download visual studio 2017 here. We changed the type of queries being generated by the grid to odata. The controllers will use entity framework to communicate with the database layer.
If nothing happens, download the github extension for visual studio and try again. In this article i will showing a complete walkthrough for creating restfull services using asp. Using web api 2 with entity framework 6 microsoft docs. How to use web api odata to build an odata v4 service without entity framework. Hi, i was struggling ealier today when having a web api call in my controller that returns a iqueryable collection from an entity framework query. With my experience so far, when i publish my webapi and then access it, the result is a json formatted file that i can open or save via a message popup similar to that shown in figure 1. Fine, now lets see how to implement an odata endpoint with our custom class. One of the hottest entity framework related topics on the web over the past few months has been about weather or not to use ienumerable or iqueryable on your repositories. In effect, you are going to stream results from the database with entity framework. The initial use for this project was in an odata, webapi and entity framework. This tutorial teaches you the basics of creating a web application with an asp. Jun 20, 2017 here mudassar ahmed khan has explained a tutorial with an example on how to use web api with entity framework database first approach model in asp.