NH3 and above allow to correct save entities in case of uni-directional one-to-many mapping without annoying save null–save–update cycle, if you set both not-null=”true” on <key> and inverse=”false” on <one-to-many> FluentNHibernate code snippet for that: public class MasterMap : ClassMap<Master> { public MasterMap() { Id(x => x.MasterId); Map(x => x.Name); HasMany(x => x.Details) .Not.Inverse() //these … Read more
When cascading from a parent to a child, NHibernate uses the SaveOrUpdate method. You are correct that NHibernate need some way to determine whether it should perform an insert or an update. It will look at three different fields for an unsaved value to determine if the entity is new. Id Version Timestamp With an … Read more
I too have encountered a similar problem and after much experimentation I noticed that when using Nhibernate to generate my schema to a file the generated column type was always length 8000. Setting setting CustomSqlType to Varbinary(max) as suggested above made no difference, however, this work around in my FluentMapping seemed to do the trick: … Read more
You’re looking for the Conjunction and Disjunction classes, these can be used to combine various statements to form OR and AND statements. AND .Add( Expression.Conjunction() .Add(criteria) .Add(other_criteria) ) OR .Add( Expression.Disjunction() .Add(criteria) .Add(other_criteria) )
Use collection interfaces instead of concrete collections, so NHibernate can inject it with its own collection implementation. In this case, use IList<int> instead of List<int>
I would like to append different point of view, not the answer how to use “future” to make only one round-trip to DB. Not sure why you need to fetch all the properties. I guess it could be 1) to be used by your code, e.g. to render UI or 2) as the API which … Read more
Yes its a common problem, you are using the Column “EndDate” twice in your mapping definition (for both Company and PrimaryListing) and that is not allowed. One of them has to go, or have an additional EndDate column (one for each association) check this too nHibernate 2.0 – mapping a composite-id *and* many-to-one relationship causes … Read more
You need to implement your own IUserType. See this blog post for details. I’ll also paste the relevant section below in case the blog disappears. In NHibernate, a custom mapping type is a class that derives from either the IUserType or ICompositeUserType interfaces. These interfaces contain several methods that must be implemented, but for our … Read more
As Matthieu says, the only case where you wouldn’t want to set inverse = true is where it does not make sense for the child to be responsible for updating itself, such as in the case where the child has no knowledge of its parent. Lets try a real world, and not at all contrived … Read more
NHibernate semantics: List: Ordered collection of entities, duplicate allowed. Use a .NET IList in code. The index column will need to be mapped in NHibernate. Set: Unordered collection of unique entities, duplicates not allowed. Use Iesi.Collection.ISet in code (NH prior to v4) or System.Collections.Generic.ISet (NH v4+). It is important to override GetHashCode and Equals to … Read more