R – What ORM should I use for a ASP.Net MVC project

asp.net-mvcorm

I am starting a new ASP.Net MVC project and was wondering what is the best Model approach to take.

Most demos recommend LinqToSQL but I know Microsoft are not really enhancing this product and are focusing more on the Entity Framework.

I like the Subsonic approach but I thought this was going to be built in with MVC with version 3 but there has been no news about the development stage of this project so I am a bit wary of using version 2 if there is to be a new release soon.

I have heard of NHibernate and Castle Record but have not had any experience at all with these and have heard numerous pros/cons for both.

Any help would be highly recommended!

Best Answer

For SubSonic, Rob just release an new MVC template which you can use when starting a new project that bakes a lot of good stuff into a new MVC project including a pre-release of SubSonic 3. Detais are available on Rob Conery's blog.

Related Solutions

The “N+1 selects problem” in ORM (Object-Relational Mapping)

Let's say you have a collection of Car objects (database rows), and each Car has a collection of Wheel objects (also rows). In other words, Car → Wheel is a 1-to-many relationship.

Now, let's say you need to iterate through all the cars, and for each one, print out a list of the wheels. The naive O/R implementation would do the following:

SELECT * FROM Cars;

And then for each Car:

SELECT * FROM Wheel WHERE CarId = ?

In other words, you have one select for the Cars, and then N additional selects, where N is the total number of cars.

Alternatively, one could get all wheels and perform the lookups in memory:

SELECT * FROM Wheel

This reduces the number of round-trips to the database from N+1 to 2. Most ORM tools give you several ways to prevent N+1 selects.

Reference: Java Persistence with Hibernate, chapter 13.

Asp.net-mvc – Compile Views in ASP.NET MVC

From the readme word doc for RC1 (not indexed by google)

ASP.NET Compiler Post-Build Step

Currently, errors within a view file are not detected until run time. To let you detect these errors at compile time, ASP.NET MVC projects now include an MvcBuildViews property, which is disabled by default. To enable this property, open the project file and set the MvcBuildViews property to true, as shown in the following example:

<Project ToolsVersion="3.5" DefaultTargets="Build" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
  <PropertyGroup>
    <MvcBuildViews>true</MvcBuildViews>
  </PropertyGroup>

Note Enabling this feature adds some overhead to the build time.

You can update projects that were created with previous releases of MVC to include build-time validation of views by performing the following steps:

Open the project file in a text editor.
Add the following element under the top-most <PropertyGroup> element: <MvcBuildViews>true</MvcBuildViews>
At the end of the project file, uncomment the <Target Name="AfterBuild"> element and modify it to match the following:

<Target Name="AfterBuild" Condition="'$(MvcBuildViews)'=='true'">
    <AspNetCompiler VirtualPath="temp" PhysicalPath="$(ProjectDir)\..\$(ProjectName)" />
</Target>

Best Answer

Related Solutions

The “N+1 selects problem” in ORM (Object-Relational Mapping)

Asp.net-mvc – Compile Views in ASP.NET MVC

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