Dapper Iqueryable

You may notice that this code uses Dapper. 2 Runtime Released We’ve tried Dapper and other lite POCO query engines but that is a maintenance cost problem when you have thousands of. Documentation 3 rd Party. ToList(); will not compile because List<> does not implement IQueryable<> IQueryable implements IEnumerable so it works. Entity Framework is an object-relational mapper that enables. And the best for the end: I have not tested this, I do not use Entity Framework currently!. Linq2Dapper. Repositories are implemented in NHibernate and EntityFramework, out-of-the-box. The IQueryable object provides remote access to the database and allows you to navigate through the data either in a direct order from beginning to end, or in the reverse order. The queries I use are in the form of predicates like so "Expression>". Use one or another. However, I'm struggling to find a viable alternative. Get generic result for simple or complex data type. 0! Since the first CTP which was released back in March, we’ve been hard at work to implement features we wanted for v5. Yo prefiero hacer una suerte de "stored procedures" en codigo usando queries encapsulados (ya sea en repositorios o en EQO). Expression) consists entirely of a single node (ConstantExpression). Please check it out instead of this one: Clean, Better, and Sexier Generic Repository Implementation for Entity Framework At first, long time ago, I have been creating all the single methods for each interface. As long as all the code inside the TransactionScope is executed on the same thread, there is no issue. The Update IQueryable extension method updates rows matching the query criteria with an expression without loading entities in the context. Learn Eval-SQL. OData is defined as "An open protocol to allow the creation and consumption of queryable and interoperable RESTful APIs in a simple and standard way" (). If you want to support any other database providers like SQLite, then you need to change in public IDbConnection Connection property. net using as. Quoting from #72110 - [21 May 15:40] Francisco Alberto Tirado Zavala: When you are working with a Client-Server application all the connections are performed by Sockets, when you create a connection you open a Socket between your client and your server. how can I add a column to IQueryable object and modify its values. Stack Exchange network consists of 175 Q&A communities including Stack Overflow, the largest, most trusted online community for developers to learn, share their knowledge, and build their careers. I hope you will enjoy these tips and tricks while programming with LINQ to Entity. 2-beta A library designed to integrate the Dapper and graphql-dotnet projects with ease-of-use in mind and performance as the primary concern. NET Boilerplate. Entity Framework Core performance tuning – a worked example (this article). Below is our dummy Employee class. NET Boilerplate on these frameworks:. Is Entity Framework 4 a good solution for a public website with potentially 1000 hits/second? In my understanding EF is a viable solution for mostly smaller or intranet websites, but wouldn't scale. 由于Dapper 本身就是轻量级Orm特性,这里参考Creating a Data Repository using Dapper dynamic queries in dapper 代码,来解决实体类与Expression> predicate问题; 您可以通过Nuget:Install-Package MasterChief. net for months in replace of entity framework. Finally, we call ToList() to get the list of Tasks. Using Async/Await with IEnumerable and Yield-Return. IQueryable is suitable for LINQ to SQL queries. net with example. IQueryable Toolkit – A must have tool if you want to build your own LINQ provider written by the mind behind LINQ to SQL. Today, I talk about a better way to implement the Unit of Work design pattern. Get generic result for simple or complex data type. Working with ORM with Code First and getting data from Store Procedures. This chapter discusses a different kind of LINQ technology, LINQ to Entities, which queries relational data managed by. 这里简单的介绍一下本人基于Dapper作的一些简单的扩展,供大家参考。为何要使用这款框架,相信大家看到下面排名就清楚了其实在各大网站上,我们大概都会看到这样的一个对比效果图,在超过500次pocose. The bonus is the repo returns an IQueryable so I have a base method in the DAL to start an IQueryable and return it and in the BL/SL I can start adding filters with the where extension methods. Linq namespace. neither of which implements IQueryable<>. The short summary is that when you include an instance method in an IQueryable it gets cached, and the methods do not get released even after your context is disposed of. Working with Stored Procedure in Entity Framework Core. NET and IQueryable. This part discusses how the translation is implemented. Download PDF. So in this scenario we need to create complex model class from multiple model classes. Dapper is the second fastest ORM. The Dapper Collection features deep blue hands, Roman numerals and a date display - details designed to give it that little something extra. After reading some pieces of code and comparing with entity framework, i think it is a waste of time because entity framework already do it. Dapper یک ORM متن باز است که برای map کردن کلاس های NET. There are quite a lot of tutorials showing how to create OData services using Web API OData, but these requires Entity Framework and a database server behind. The reason why we developed RepoDb and is using Dapper is to avoid the slow IQueryable of Microsoft. In this example, LINQ to SQL (using the default generic Query) would try to convert the query to SQL and execute it on the server. NET, JavaScript, and C++. net The performance implications of IEnumerable vs. Even after all these years, I'm still a big fan of ORMs. - landmarkhw/Dapper. For a few years I had my own blog over on Blogger and it worked well, but the time came for me to build my own. The Repository Pattern has gained quite a bit of popularity since it was first introduced as a part of Domain-Driven Design in 2004. NET driver for use with a specific version of MongoDB. The previous parts has discussed some aspects that can impact the performance of EF/Core and LINQ to Entities, and here is a summary: Remote LINQ to Entities query can have better performance than local or hybrid query. Hi, I have a Web API to retrieve records from Inventory and perfectly wroking. Let us learn it practically how to convert LINQ query result to Datatable by creating one simple application as Now create the project as: "Start" - "All Programs" - "Microsoft Visual Studio 2010". Find out most popular NuGet graphql Packages. I agree that exposing IQueryable until you're read for your data is ok. Unfortunately, when I call "byRecID" from the winform, "SingleOrDefault" is not available, but IS available inside 'byRecID' method, so I can't just return IQueryable, needs to be the typed IQueryable (because SingleOrDefault not an extension of IQueryable, only IQueryable). ToList(), ToArray() etc. I built this site using C#, ASP. The library offers a fluent builder way to create queries with Dapper. You should already have read at least the CSharp Driver Tutorial introduction to the C# driver. Some are angry opinion pieces from people who don’t like one technology or the other and clearly haven’t run any tests. Piccolo problema affrontato al volo oggi: Un client WCF non raggiunge un server quando tra i due c'è un proxy che richiede autenticazione. We’ve released the second CTP for LLBLGen Pro v5. Dapper forces you to write raw SQL in the code, and if your’re looking for DAL that is similar to Dapper but with real isolation from the database (SQL commands generation), take a look to the NReco. EF Core provides the following methods to execute a stored procedure: DbSet. As performance becomes more important, it does, however, require some knowledge of the traps that you need to avoid, and of the wrinkles that impact performance. LINQ provides us some extension methods to convert an IEnumerable to a collection e. Short answer: Neither, because those are uncomparable. IQueryable 33. Now if you do not care about exposing IQueryable to the caller (which I doubt), obviously just change your params argument for a Func, Queryable> addIncludes argument, and avoid coding all those things above. Is there a plan to make Dapper. While this does not work out of the box with MVC 5, I have provided a workaround that should help. The database connection must also be open when IQueryable. Here’s why – 1. The library offers a fluent builder way to create queries with Dapper. Almost all of generic repository pattern tutorials were making use of EF, so I haven't got much sources to compare my code with. Sqlite database provider allows Entity Framework Core to be used with to be used with SQLite. So at best its just a Dapper Helper. Merhaba arkadaşlar bu yazımızda CQRS pattern ve dapper ile nasıl generic bir data katmanı yazabiliriz onu inceleyeceğiz. Entity Framework(EF)では,DBへのデータの挿入,読み出し,更新,削除といった基本的な操作はDbContextを通じて行います.. In previous articles I explained asp. Additional performance benchmark data for a variety of data access methods can be found on the Dapper site. NET 5: Jump Start to AngularJS with MVC 6 Web API 10 June 2015 on ASP. Each post builds on the last one. CQRS patternimizi uygulayabilmek için Command ve Query sınıflarımızı ayırmamız gerekiyor. Dapper, Dapper Extensions and Linq. A simple lightweight Linq provider for Dapper. City == "Delhi" select customer; lstCus. Maybe you implemented a generic repository, or used a base class. Dapper is a micro ORM that really just provides for the mapping from result sets into entities; it has no ability to generate schemas or get you out of writing SQL. 为什幺使用 testName VARCHAR(50) NULL INSERT INTO Test VALUES('周公瑾') IEnumerable Get (string sql, Func map, dynamic param = null, IDbTransaction transaction = null, bool buffered = true, string splitOn = "Id", int?IList GetAll();数据连接工厂 /// 数据库类型 public static void Init(string conectionString, DatabaseType dataBaseType = DatabaseType. NET Core as mentioned in this tutorial. You have to explicitly design for testability. This is part of a series on using generics in C# to make code more resuable. IE a single Course will have multiple Assessments. The IQueryable interface is intended for implementation by query providers. Expressmapper - lightweight, lighting fast and easy to use. Get generic result for simple or complex data type. How can I convert my list of customers to the IAsyncEnumerable? For reference, the IEntityReader interface is defined such as:. Find out how to import and export excel in ASP. For example, with Entity Framework, the following LINQ statement, the SQL query. Its very light weight and does some basic mappings. IQueryable is suitable for querying data from out-memory (like remote database, service) collections. NET MVC 3 project: public ActionResult Index(string searchWord, GridSortOptions gridSortOptions, int? page) { var userListModel = new PagedViewMode. GetAll() used here returns an IQueryable to query entities. By doing so they get no benefit over using the OR/M directly. Sqlite database provider allows Entity Framework Core to be used with to be used with SQLite. NET and own the title of King of Micro ORM in terms of speed and is virtually as fast as using a raw. Just a DbContext wich initialize connection and multiple DbSet wich queries tables using Dapper and an implementation of iqueryable to "generate" SQL based on given link expression using dapper sqlbuilder. This is the first in a series of posts on how to build a LINQ IQueryable provider. در ضمن نمونه ضمیمه این مقاله شامل تمام پیاده سازی های سری مقاله های چرخه حیات در mvc می باشد. Note, the ToList() method returns an IQueryable interface, in order to provide LINQ style manipulation of data prior to SQL query execution, so the NHibernate LINQ reference will be needed. Dapper’ı projelerimize nuget package manager üzerinden aşağıda ki nuget komutu ile referans edebiliriz. Short answer: Neither, because those are uncomparable. IQueryable is not observable by default, therefore adding/removing and items will not automatically update UI control, e. Linq paket add Dapper. - BillRob Oct 28 '13 at 23:02. NET MVC 3 project: public ActionResult Index(string searchWord, GridSortOptions gridSortOptions, int? page) { var userListModel = new PagedViewMode. I must confess that in the past I’ve made the mistake of using EF for things where EF was a bad decision, and where Dapper would be a better fit. Entity Framework Classic is a supported version from the latest EF6 code base. If the provider does not also implement IQueryable, the standard query operators cannot be used on the provider's data source. This is more about writing more fluent (but not 100% fluent) queries. Na szczęście Dapper ma wsparcie dla Geography i nie trzeba samemu tworzyć powyższych zapytań. 为什幺使用 testName VARCHAR(50) NULL INSERT INTO Test VALUES('周公瑾') IEnumerable Get (string sql, Func map, dynamic param = null, IDbTransaction transaction = null, bool buffered = true, string splitOn = "Id", int?IList GetAll();数据连接工厂 /// 数据库类型 public static void Init(string conectionString, DatabaseType dataBaseType = DatabaseType. Expressmapper - lightweight, lighting fast and easy to use. I found an example in the VS2008 Examples [1] for Dynamic LINQ that allows you to use a sql-like string (e. Dapper has much smaller footprint than NHibernate or Entity Framwork. They can hold the entire code for a query, or for complex queries it might hold just part of a query. There are built-in samples in LINQPad - go to the 'Samples' tab and expand 'C# in a Nutshell', Chapter 10. The goal of this library is to keep your POCOs pure by not requiring any attributes or base class inheritance. このご時世に DataTable かよ、という感じもしますし、私自身実案件では Dapper をメインで使用しているわけですが、少しは使える場面もあるかもしれません。. Batch Update Problem. Get generic result for simple or complex data type. AsEnumerable()). IQueryable. Julie Lerman presents some performance data in her May 2016 MSDN article Dapper, Entity Framework, and Hybrid Apps. I hate when I'm writing a straight SQL query in a string literal and misspell one of the column names, because everything will compile and unit tests will pass, and the mistake isn't caught until I run integration tests. IQueryable is best to query data from out-memory (like remote database, service) collections. ExecuteSqlCommand(). Um, wait a second… orderDetails is an IQueryable object, so where does Dump come from? Dump is an extension method provided by LINQPad. Using Async/Await with IEnumerable and Yield-Return. IQToolkit is essential if you are building your own LINQ IQueryable provider. cs文件,编译后就40多K的一个很小的Dll. From("x as A")), I will receive exception. Contribute to StackExchange/Dapper development by creating an account on GitHub. O/R マッパーでなくて SQL だけを作ってくれるヘルパーが欲しいなぁと思いまして(具体的には Dapper に食わせる SQL を作りたい)、SQL Builder 的なものを探してみました。. Yo prefiero hacer una suerte de "stored procedures" en codigo usando queries encapsulados (ya sea en repositorios o en EQO). You may notice that this code uses Dapper. If some provide IQueryable interface then clients expect full implementation. Documentation is available, as well as an example on GitHub. This is by design. It is almost the same as Dapper as we are use into it already. Dapper简单介绍: Dapper is a single file you can drop in to your project that will extend your IDbConnection interface. IQueryable and IQueryable IQueryable and IQueryable are used to build specific query against a specific data source, like SQL Server, etc. IQueryable is suitable for querying data from out-memory (like remote database, service) collections. WhereIf is an extension method of ABP to simplify conditional usage of IQueryable. but, the story is different in Dapper. NET Core MVC in combination with any modern data access layer, it should be extremely easy to pass your cancellation token and cancel long running queries when a request from the client is aborted. 数据库刚刚从Sql Server迁往PostgreSQL dapper是个很适合高级DBA或者对性能苛刻的. So now I want to write a Stored Procedure (I already have it name GetInventory) and use it inside the web api. Telerik® UI for ASP. I leaked Entity Framework into my domain services, because [] Fail. I blogged a bit about it here: Exposing IQueryable in a CQRS Query Stack. relationship e. Dapper is a simple micro-ORM nuget available as a alternative for heavy duty queries. CQRS patternimizi uygulayabilmek için Command ve Query sınıflarımızı ayırmamız gerekiyor. Documentation is available, as well as an example on GitHub. I would use Dapper for this. But Entity Framework has a very neat property: "The deferred execution of a query through the IQueryable interface". net mvc model validation with data annotations with example, asp. Jon Galloway posted a nice how-to video here. May 10, 2015 June 11, 2015 Takaloy Leave a comment. Dapper is a micro-ORM: it does not offer the full range of features of a full ORM such as NHibernate or Entity Framework. However, the method doesn't let you use LINQ queryable methods like Where to filter entities to include which is a major drawback. I built this site using C#, ASP. while in EF this is totally doable thanks to `IQueryable` 3. Mister performance created a big fat performance mess. Is Entity Framework 4 a good solution for a public website with potentially 1000 hits/second? In my understanding EF is a viable solution for mostly smaller or intranet websites, but wouldn't scale. net check arraylist contains value in c#, vb. Hi, I have a Web API to retrieve records from Inventory and perfectly wroking. So clearly I shouldn't be using IQueryable as a return type for my first QueryProject abstraction. Optimize EF (except for bulk) or drop down to linq2db or even further to dapper/petapoco/massive. For some reasons, when I call. It is only supposed to be implemented by providers that also implement IQueryable. The LINQ provider implements the IQueryable interface for querying relational data stores. Before going to write the code, let's understand the repository and unit of work patterns separately. I would like to have feedback from my blog readers. 工作单元模式是“维护一个被业务事务影响的对象列表,协调变化的写入和并发问题的解决” 比如:新入校一个同学,需要在班级,学校,学生,课程等多个表里同时操作。. Supporting sorting + criteria + pagination. It’s taken a bit longer than expected as the main feature, Derived Models (more on that below), turned out to be a bigger. DbContextとエンティティの状態¶. By doing so they get no benefit over using the OR/M directly. NET ORM is considered to be the fastest ORM as it directly executes the RAW SQL without any additional overhead. I just recently discovered the Dapper micro-ORM for doing data access in applications. It’s an anti-pattern and I don’t care for it personally, but I can see how it could be useful. Linq Download (Unzip the "nupkg" after downloading). [SearchMovies] [email protected] int = null, @CategoryIds varchar(50) = null, @Keywords nvarchar(4000) = null, @PageIndex int = 1, @PageSize int. This is an updated article that takes account of a) the release of Entity Framework Core (EF Core) and b) further investigations of different EF Core database access patterns. Create a convention for ids using dapper. So no, Dapper can not return an IQueryable. javascript. This allows any C# project (WPF, Silverlight, ASP. Contact me at vmsdurano at gmail dot com. 有高手试过Dapper在SQLServer下多表联读时的分页问题吗? SQL语句作用:读一用户的收藏(关注其他用户)记录,同时将关注者和被关注者的用户信息一并读出,实现分页。. Раздел, посвященный программированию на языке C# и платформе. A dev shows us how to work with the new compiled queries offered in the Entity Framework Core 2. but, the story is different in Dapper. NET? This library will work with any data source that you provide. Get started with Dapper, Dapper Plus, and other third parties libraries. Patrick Kalkman My latest article: RegiRide, a complete Windows Phone application. GraphQL for. Volare also learned our business practices and made the building of the site a pleasure instead of a project. TransactionScope object in. In this post we make some big decisions about the data access layer and compare coding manually vs. How to use Dapper with Linq I'm trying to convert from Entity Framework to Dapper to hopefully improve data access performance. For querying SQLite, MySQL and Oracle (via the optional plug-in), LINQPad uses Matt Warren's IQueryable toolkit. The problem is that LINQ to Entities doesn't understand how to convert that Select overload (the one that gives you the index) into a SQL query. while in EF this is totally doable thanks to `IQueryable` 3. IQueryable is a live query and needs and open database connection. I don't know how to do it properly. nuget-install Dapper. NET Standard. This chapter discusses a different kind of LINQ technology, LINQ to Entities, which queries relational data managed by. The previous part demonstrated what are the SQL translations of the LINQ to Entities queries. I hope you will enjoy these tips and tricks while programming with LINQ to Entity. Notice how we can navigate through the properties (customer, details, etc. Linq namespace. NET Boilerplate. This feature is now available on Entity Framework Classic - Query Deferred. 由于Dapper 本身就是轻量级Orm特性,这里参考Creating a Data Repository using Dapper dynamic queries in dapper 代码,来解决实体类与Expression> predicate问题; 您可以通过Nuget:Install-Package MasterChief. With Entity Framework, "Include" method is often used to load related entities / child collections. EntityFrameworkCore. We also pass in two arguments. 0 supports the. NET 5: Jump Start to AngularJS with MVC 6 Web API 10 June 2015 on ASP. Dapper یک ORM متن باز است که برای map کردن کلاس های NET. Dynamic的动态拓展,我自己再对Expression进行联表拓展,可以说满足绝大多数应用场景。至于那. Example 4-9 , however, returned an anonymous type with two properties. EF Core – Combining SQL and NoSQL for better performance. There lots of exceptions of impossibility to convert to T-SQL code. Hello, Is Dapper going to support Expression Trees and IQueryable interfaces? If no, are there workarounds to be able to prepare filters on my queries before sending them for execution at SQL Server?. Раздел, посвященный программированию на языке C# и платформе. 这里简单的介绍一下本人基于Dapper作的一些简单的扩展,供大家参考。为何要使用这款框架,相信大家看到下面排名就清楚了其实在各大网站上,我们大概都会看到这样的一个对比效果图,在超过500次pocose. This is by design. the first paragraph says it all. public class SourceOuterObject { pub. Get started with Dapper, Dapper Plus, and other third parties libraries. Örneğimize Core projemizi yazmakla başlayacağız. Also make sure that the repository implementation does not return IQueryable value hidden as IEnumerable one. It’s an anti-pattern and I don’t care for it personally, but I can see how it could be useful. NET Boilerplate. I have seen a case where a developer wrote a LINQ query with Func delegate which will get the data from the database and returns back to the UI. But what if you want to convert the enumerable to a DataTable. It will allow you to avoid writing all the plumbing code. Empid == 2). This is more about writing more fluent (but not 100% fluent) queries. The C# compiler compiles queries that target such data sources into code that builds an expression tree at runtime. You may notice that this code uses Dapper. Entity Framework Core performance tuning - a worked example (this article). You need to update one or millions of records based on a query criteria and an expression. Whether you favor IQueryable depends on your preferences and needs. Almost all of generic repository pattern tutorials were making use of EF, so I haven't got much sources to compare my code with. ToList(); will not compile because List<> does not implement IQueryable<> IQueryable implements IEnumerable so it works. IQueryable接口是继承自IEnumberable接口的。 本案例详细介绍了EF、Dapper等ORM轻量级开发框架在ASP. So now I want to write a Stored Procedure (I already have it name GetInventory) and use it inside the web api. 2 Entity Framework Alternatives (or Give Me Data!) - DZone Database. Dapper is a micro ORM that really just provides for the mapping from result sets into entities; it has no ability to generate schemas or get you out of writing SQL. It provides us an infrastructure to develop applications in best practices. com choose Micro ORM dapper). A small library that complements Dapper by adding basic CRUD operations (Get, Insert, Update, Delete) for your POCOs. I need to bind this list to a ComboBox. The provider is maintained as part of the Entity Framework Core Project. I share the repository here and hope someone could improve it i. That motivates us to continue to grow and improve all our projects. The client sends these parameters in the query string of the request URI. The value of IQueryable in e. In this case, Dapper still outperforms EF Core, but only slightly. An intuitive example is Last query for a table data source, which could query. Hi, Lightspeed uses IQueryable for Db items. NET Boilerplate uses the ambient TransactionScope approach by default, but it also has a built-in implementation for the DbContext transaction API. Stack Exchange network consists of 175 Q&A communities including Stack Overflow, the largest, most trusted online community for developers to learn, share their knowledge, and build their careers. It is a great and faster alternative to Automapper and other. Dapper’s primary feature is mapping from. NET Standard version 1. عملیات CRUD با استفاده از Dapper ORM در MVC. Only sources that implement IAsyncEnumerable can be used for Entity Framework asynchronous operations. 工作单元模式是“维护一个被业务事务影响的对象列表,协调变化的写入和并发问题的解决” 比如:新入校一个同学,需要在班级,学校,学生,课程等多个表里同时操作。. Kasım 8, 2017 Aralık 15, 2017 CQRS Pattern, Dapper, Design Patterns, Generics Yorum bırakın CQRS Dapper Design Patterns Dapper. NET Core 1, CodeProject Advertise here. Improving EF Core performance with Compiled Queries 20 September 2017 Comments Posted in ef core, performance. But what if you want to convert the enumerable to a DataTable. I'm having an issue with a particular type of mapping. Why Dapper. Maybe you implemented a generic repository, or used a base class. Creates a Dictionary from an IEnumerable according to a specified key selector function, a comparer, and an element selector function. IQueryable can move forward only over a collection, it can't move backward and between the items. So for I have an ODataQueryOptions parameter on the server side that I can use to look at the FilterQueryOption. Na szczęście Dapper ma wsparcie dla Geography i nie trzeba samemu tworzyć powyższych zapytań. Asynchronous Database Calls With Task-based Asynchronous Programming Model (TAP) in ASP. LINQ to Objects in C# LINQ to Objects means that we can use LINQ to query objects in a collection. In this post, I’ll show you what happens when you use a func delegate on the Entity Framework entities. cs Find file Copy path brentmannering Restructered solution, updated readme, plus added support for JOIN's etc a430242 Aug 26, 2017. net and I'm liking it. Dapper, is a micro ORM tool. by Joe Albahari, Matt Warren, WiCKY Hu Version 2. NET Core library designed to integrate the Dapper and graphql-dotnet projects with ease-of-use in mind and performance as the primary concern. In generic classes and methods,given a variable t of a parameterized type T, the statement t = null is only valid if T is a reference type and t = 0 will only work for numeric value types but not for structs. In LINQ, expression trees are used to represent structured queries that target sources of data that implement IQueryable. See the following documents to implement repositories in ASP. NET developers to work with relational data using domain-specific objects. عملیات CRUD با استفاده از Dapper ORM در MVC. NET Boilerplate uses the ambient TransactionScope approach by default, but it also has a built-in implementation for the DbContext transaction API. This allows any C# project (WPF, Silverlight, ASP. How do I use XYZ ORM/database with GraphQL. There are quite a lot of tutorials showing how to create OData services using Web API OData, but these requires Entity Framework and a database server behind. چرخه حیات MVC (بخش چهارم) در این مقاله ضمن توضیح الگوی طراحی Factory به پیاده سازی یک CustomController توسط این الگو خواهیم پرداخت. Um, wait a second… orderDetails is an IQueryable object, so where does Dump come from? Dump is an extension method provided by LINQPad. The problem is that many developers fail to understand the patterns purpose and create repositories which leak persistence specific information up to the caller (typically by exposing IQueryable). For these reasons, I like use Dapper for Reporting Queries (where I may not need a DTO), batch operations, and very-simple operations where I don’t need to benefit from ORM strongly-typing. GitHub Gist: instantly share code, notes, and snippets. , ItemsControl (WPF) I tried to wrap-around IQueryable to ObservableCollection, but it didn't work. Where(x = > x. From("x as A")), I will receive exception. Is Dapper an ORM? Yes and no! People are still arguing about it. Thanks for reading. How to use Dapper with Linq I'm trying to convert from Entity Framework to Dapper to hopefully improve data access performance. Entity Framework (EF) and Dapper both are object-relational mappers that enable. IQ Driver - for MySQL, SQLite, Oracle.