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    <p>I don't think this will be that easy. Though there are generators able to read a database schema and generate appropriate mapping and classes this would only result in an access layer for your existing eav db. To generate a relational version of this db you then would have to read the data and create new domain objects containing properties for the the values set in your db. This could most likely result in one big table containing all the properties exist in the eav db. Therefor I think a better approach would be to create a relational DB model by hand analysing the existing data and considering the needs of your application. Especially Table inheritance should be your friend here. Then after you have created access layers for both schemas you still would have to write a mapping for data migration.</p>
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    1. POCan nhibernate/orm support eav?
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    1. USzoidbeck
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    1. COWith nHibernate you can map entities to classes in such a way that it isn't a 1:1 mapping with the db schema so you don't have to strongly couple yourself to the database. I just can't see a way at the moment of mapping multiple rows, one for each property to a single object. Typically you'd have one row which contained the data for a single object.
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      1. USspooner
    2. COI know, but i don't see any possibility to do what you want in an other way than that you already mentioned. You are able to use filter-prop on many-to-one's but imo that wouldn't help anything, also i don't think this would help to fix your performance problem anyway. Maybe i got you wrong but as i understood you are considering to refactor your eav to a relational or mixed schema. If you only keep the rare props as eavs in a bag/set you could make them lazy to only load on demand.
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    3. COThe issue is we really don't need a property bag, it's only our developers who will add new properties, we don't expect a user to extend the model. Basically the system I've inherited is built off a framework with this EAV structure in place. We want a totally normalised model going forward. I was hoping that we'd be able to perform a mapping in the way I suggested as we could then baseline the domain model and then start doing the database work. From what you are saying this isn't possible, which is a shame, as it seems the only other solution is a hand crafted DAL.
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