For the rest of the book, we explore nhibernate using a more sophisticated example. Inheritance mapping strategies in fluent nhibernate codeproject. Mapping inheritance learning nhibernate 4 packt subscription. Following is a slimmed down version of the class diagram from. An example of fluent nhibernate auto mapping in action.
Fluent nhibernate framework is a great framework, where you can specify strongly typed mapping in the form of classes on the top of nhibernate framework. Net, the book is based on mannings bestselling hibernate in action. Fluent nhibernate defaults to using tablepersubclass strategy for automapping inheritance hierarchies. Fluent nhibernate automapping inheritance and ignoring an abstract property.
Fluent nhibernate and inheritance mapping while exploring the adventureworks database i have found an interesting case where inheritance mapping has to be used. To ignore the property altogether you need to call instance. Fluent nhibernate is external to the nhibernate core, but is fully compatible with nhibernate version 2. Nhibernate s implementation of table per subclass does not require a discriminator column. Please note that this way of configuring fluent nhibernate is obsolete since the rcs. Using this principle, the auto mapper inspects your entities and makes assumptions of what particular properties should be. You can then make use of implicit polymorphism to achieve polymorphism across the whole hierarchy.
With some reading at this fabio post, this other one, and this one too, i wrote my own sample just to see what we can do even if we can use mapping by code to map class by class the entire model, something more. Its a fluent interface that allows you to map your entities completely in code, with all the compiletime safety and refactorability that brings the getting started guide has a good introduction to mapping with the fluent interface. Youve reached the official wiki for fluent nhibernate. Fluent mapping is the namesake mapping style that fluent nhibernate uses. Getting started fluentnhibernatefluentnhibernate wiki. I always hear good things about nhibernate and how it is better than alternatives such as entity framework so i decided to try it out for myself. Fortunatelly, fluent nhibernate provides possibility for automatic mapping creation so called automappings. Fluent nhibernate automappings ignore inherited property stack. If this is not what you want, then you can modify your configuration to specify with types use a discriminator and therefore are tableperhierarchy. I know this is really old, but it is now pretty simple to set up fluent to generate the exact mapping you initially desired. Getting started with fluent nhibernate and auto mapping in.
Creating database and model in order to show you, how to configure automappings in fluent nhibernate, lets create simple database along with model classes. There are two main things that youd want to do with inherited classes, either ignore the base class all together, or map them using an. Using this principal, the auto mapper inspects your entities and makes assumptions of what particular properties should be. Covers only the basics of using automapping, schema generation, and basic nhibernate crud actions. Six weeks ago, when i started my experiments with nhibernate s 3. Hello, fluent nhibernate experts please help me, i am using fluent nhibernate in my project. Nhibernate supports the three basic inheritance mapping strategies. Fluent nhibernate offers a simplified implementation of nhibernate without using the xmlhbm mapping files. Background nhibernate is an object relational mapping framework, which as. Fluent nhibernate samples auto mapping part 12 nov 4. This of course was a snarky in the moment tweet as is the title of this post, but i do actually think that auto mapping is the best usage pattern for fluent nhibernate. To start with weve mapped the id column, and told fluent nhibernate that its actually an identifier. This is an excerpt from the auto mapping wiki page.
Contribute to fluentnhibernatefluentnhibernate development by creating an account. We can add other conventions here, but all we need to get our application running is. It is based on hibernate which is a popular java objectrelational mapper and it. Solved fluent nhibernate automapping sample needed. Quick intro to fluent nhibernate, resource links, and a working downloadable selfcontained sample. Net objectrelational mapper and is distributed under the gnu lesser general public license. Fluent nhibernate is cool because there is too much xml in the world so i appreciate any. Early access books and videos are released chapterbychapter so you get new content as its created. Our mapping is complete, fluent nhibernate automatically assumes that any inherited classes that havent had their basetype excluded by the isbasetype convention should be mapped as joinedsubclasses. After some internal conversations at work, i tweeted that using classmaps with fluent nhibernate is the the wrong way to approach the problem. This allows for easy refactoring, improved readability and more concise code. While on my machine everything works fine, when i publish my project to my hosting server, im having some issues.
The following code will prevent a column from generated in your database. Fluent nhibernate will see that your id property has a type of int, and itll automatically. Fluent nhibernate has a concept called auto mapping, which is a mechanism for automatically mapping all your entities based on a set of conventions. Following is a slimmed down version of the class diagram from our domain model representing this inheritance relationship. Automapping inheritance fluentnhibernatefluentnhibernate wiki. Auto mapping, overrides and alterations 10 feb 2009. So, heres the domain model ill be using in this blog post to show couple of fnh auto mapping aspects. Tvpff rpvn ndeief mapping metadata er kfrf uhbeertnia eqw shtee aelsssc ngz. As we know, there are few different approaches to inheritance in database. Readonly method tells fnh to not look for changes on the property in the database. The tph inheritance depends on a conditional mapping which is defined by a condition such as a discriminator database field.
In this sample, we want to define a very basic domain model, map the model using automapping as provided by fluent nhibernate, and then let nhibernate generate. Fluent nhibernate offers an alternative to nhibernates standard xml mapping files. In the classic style of mannings in action series, nhibernate in action introduces. Next article in ayendes nhibernate mapping series is about inheritance mappings. Fluent nhibernate allows us to bypass this laborious step with auto mappings. Conceptually this is similar to fluent nhibernate and the code first mapping in entity framework. Auto mapping fluentnhibernatefluentnhibernate wiki. Auto mapping utilises the principle of convention over configuration. When using automapping, fluent nhibernate tries to add this column to the table. Fluent nhibernate is another way of mapping or you can say it is an alternative to nhibernate s standard xml mapping files. I really liked fluent nhibernate but i had a hard time getting used to the outofthebox mappingbycode feature. I want to try with automappings in fluent nhibernate. More fun with fluent nhibernate automapping simple example of using fluent nhibernate automapping nhibernate is a flexible and adaptable framework. The x in this example is an instance of employee that fluent nhibernate uses to retrieve the property details from, so all youre really doing here is telling it which property you want your id to be.
How to use fluent nhibernate with auto mappings daveden. If you want to have your baseclass included in nhibernate, then just dont include the ignorebase above. Normally, nhibernate uses xml files to determine how each entity in the domain model relates to each table in the database. It is possible to use different mapping strategies for different branches of the same inheritance hierarchy. Thats how to deal with baseclasses with fluent nhibernate s auto mapping. Fluent nhibernate offers an alternative to nhibernate s standard xml mapping files. Introduction writing mappings for models in large application is quite boring task. Fluent nhibernate is cool because there is too much xml in the world so i appreciate any initiative to bring down the amount of xml. Look here for an example on how to customize the automapping on fluent nhibernate 1. Fluent mapping fluentnhibernatefluentnhibernate wiki github. My first impression about mappingbycode was that it seems to be a good direction, but its still immature and whats important not documented at all. Auto mapping utilises the principal of convention over configuration. Also thank you ayende for doing these posts i am finding them great for reference.
Override for fluent nhibernate for long text strings nvarcharmax not nvarchar255 6 when ever you set a string value in fluent nhibernate it alwasy sets the db vales to nvarchar255, i need to store quite a lot of long string which are based on user inputs and 255 is impractical. Once youve read that then you should be able to find a bit more detail here. Mssqlconfiguration, autopersistencemodel, sessionfactory, and itransaction. This code uses automapping, configuration connection string, overrides and automapping inheritance. The root class billingdetails of the inheritance hierarchy is mapped to the. Auto mapping fluentnhibernatefluentnhibernate wiki github. Fluent nhibernate automap inheritance with subclass relationship. It is recommended you refer to those pages for the latest version of this content, as this blog post will not be maintained for correctness. In our domain model, we have all classes representing a benefit inherited from the benefit class. Getting started fluentnhibernate fluent nhibernate wiki. Net developers to the nhibernate objectrelational mapping tool. Explore the full potential of nhibernate to build robust data access code.
Automapping inheritance for how to handle inheritance with the. Its a fluent interface that allows you to map your entities completely in code, with all the compiletime safety and refactorability that brings the getting started guide has a good introduction to mapping with the fluent interface, and the detail provided here builds upon that introduction. Recently ive found some time to check out nhibernate s 3. In this post i would like to show how it can be neatly mapped with fluent nhibernate. Nhibernate in action begins by describing how to implement persistence in a layered. Fluent mapping fluentnhibernatefluentnhibernate wiki. Ill cover the following topics in the code samples below. Inheritance mapping with fluent nhibernate stack overflow. This is used for the domain model and is not a column in the database table.