CODEWITHSUNDEEP
nhibernate
Phil Whittaker
Phil Whittaker

Reputation: 434

Test a collection is Many to many or many to one

Is there anyway for me to test if a collection is a many to many or many to one relationship from the session.

I have got as far as using the

SessionFactory.GetClassMetadata(type)

which gives the PropertyTypes collection but this doesn't distinguish between many to many and many to one where as one to many is catered for

Upvotes: 2

Views: 179

Answers (1)

Radim Köhler
Radim Köhler

Reputation: 123861

The below code, will iterate TheEntity property names, to find the mapped collections. Then, it will ask for Collection persister and get informed about One-to-Many or Many-to-Many

var persister = factory
    .GetClassMetadata(typeof(TheEntity)) as AbstractEntityPersister;

// iterate property names
foreach (var propertyName in persister.PropertyNames)
{
    // find type
    var index = persister.GetPropertyIndex(propertyName);
    var propertyType = persister.PropertyTypes[index];

    // check if it is collection
    if (!propertyType.IsCollectionType)
    {
        continue;
    }

    // the Role is
    // the Entity type Name & the Collection name
    var roleName = persister.Name + "." + propertyName;

    // the Abstract collection persister
    var collectionPersister = factory
        .GetCollectionMetadata(roleName) as AbstractCollectionPersister;

    // here we go:
    var isManyToMany = collectionPersister.IsManyToMany;
    var isOneToMany = collectionPersister.IsOneToMany;

}

Note: I guess that in your question the Many-to-One (which is the reference not collection mapping) should be One-to-Many

Upvotes: 1

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