I have a class Client which has a attribute of dogs
public class ClientsMap : ClassMap<Clients>
{
public ClientsMap()
{
Id(x => x.ClientID);
HasMany(x => x.Dogs);
}
}
public class Client
{
public virtual IList<Dog> Dogs { get; set; }
public virtual int ClientID { get; set; }
}
and a class of dog that references client.
public class Dog
{
public virtual Clients Client { get; private set; }
public virtual int Id { get; set; }
}
public class DogMap : ClassMap<Dog>
{
public DogMap()
{
Table("Pooches");
Id(x => x.Id);
References(x => x.Client).Column("ClientId");
}
}
Because I am mapping on to an existing DB i cannot change the field names.
When I try and return the dogs collection I am getting an invalid column error on client_id with the SQL
SELECT
dogs0_.Clients_id as Clients3_1_,
dogs0_.Id as Id1_,
dogs0_.Id as Id1_0_,
dogs0_.ClientId as ClientId1_0_
FROM
pooches dogs0_
How can I make this use clientid over cliet_id. I thought I specified this in the dogs map.
You should also specify the column name on the one to many relationship.
HasMany(x => x.Dogs)
.KeyColumn("ClientId");
Related
I'm having a problem with the following scenario.
My class structure is as follows:
public class Owner
{
public virtual Guid Id { get; set; }
public virtual string Name { get; set; }
public virtual IList<Vehicle> Vehicles { get; set; }
}
public abstract class Vehicle
{
public virtual long Id { get; set; }
public virtual string Name { get; set; }
}
public abstract class PoweredVehicle : Vehicle
{
public virtual string EngineType { get; set; }
}
public class Car : PoweredVehicle
{
public virtual int Doors { get; set; }
}
public class Truck : PoweredVehicle
{
public virtual long MaxLoad { get; set; }
}
public class Bicycle : Vehicle
{
public virtual int FrameSize { get; set; }
}
Fluent mappings:
public class OwnerMap : ClassMap<Owner>
{
public OwnerMap()
{
Id(x => x.Id).GeneratedBy.GuidComb();
Map(x => x.Name);
HasMany(x => x.Vehicles);
}
}
public class VehicleMap : ClassMap<Vehicle>
{
public VehicleMap()
{
Id(x => x.Id).GeneratedBy.HiLo("10");
Map(x => x.Name);
UseUnionSubclassForInheritanceMapping();
}
}
public class PoweredVehicleMap : SubclassMap<PoweredVehicle>
{
public PoweredVehicleMap()
{
Map(x => x.EngineType);
Abstract();
}
}
public class CarMap : SubclassMap<Car>
{
public CarMap()
{
Map(x => x.Doors);
}
}
public class TruckMap : SubclassMap<Truck>
{
public TruckMap()
{
Map(x => x.MaxLoad);
}
}
public class BicycleMap : SubclassMap<Bicycle>
{
public BicycleMap()
{
Map(x => x.FrameSize);
}
}
I insert a Car and a Bicycle. When I try to insert an Owner with a list of Vehicle objects (with a Car and a Bicycle), I get the following error:
Exception: NHibernate.Exceptions.GenericADOException: could not insert
collection:
[NHibernateTest.Owner.Vehicles#8ace95bc-ad80-46d7-94c7-a11f012b67c6][SQL:
UPDATE "Vehicle" SET Owner_id = #p0 WHERE Id = #p1] --->
System.Data.SQLite.SQLiteException: SQLite error
Since I setup table per concrete class, why is NHibernate trying to update a non-existing table, which is representing the base class? Is this type of mapping not supported for this scenario?
Also, when I change from HasMany to HasManyToMany, this works fine.
In this case the only choice is Inverse() mapping. This means that the concrete Vehicle (Car, Bicycle) must care about the persistence of the relationship.
To enable this, extend the Vehicle class with new property:
public abstract class Vehicle
{
..
// new owner independent navigation property
public virtual Guid OwnerId { get; set; }
}
and extend mapping of the Vehicle
public VehicleMap()
{
..
Map(x => x.OwnerId).Column("Owner_id);
}
and finally invert persistence responsibility. Not the owner, but the collection item will care about correct Owner_id column changes (when concrete Vehicle insert/update is invoked).
(more about inverse: https://stackoverflow.com/a/1454445/1679310)
public OwnerMap()
{
..
HasMany(x => x.Vehicles)
.Inverse()
.Cascade.All();
}
When Vehicle is added into Owner's collection, its OwnerId must be also assigned:
owner.Vehicles.Add(car);
car.OwnerId = owner.Id;
I attempted to extract some common properties to a base class and map with Fluent Nhibernate. In addition, I also attempted to add a second level of inheritance.
//Base entity class
public class EntityBase : IEntityBase
{
public EntityBase()
{
CreatedDate = DateTime.Now;
}
public virtual DateTime? CreatedDate { get; set; }
public virtual int Id { get; set; }
public virtual int Version { get; set; }
}
//Base Entity Mapping
public class EntityBaseMap: ClassMap<EntityBase>
{
public EntityBaseMap()
{
UseUnionSubclassForInheritanceMapping();
Id(x => x.Id);
Version(x => x.Id);
Map(x => x.CreatedDate);
}
}
//first sub class of EntityBase
public class Actuate : EntityBase, IActuate
{
public virtual DateTime? ActivatedOn { get; set; }
}
//Actuate Mapping class
public class ActuateMap : SubclassMap<Actuate>
{
public ActuateMap()
{
Map(x => x.ActivatedOn);
}
}
//Sub class entity
public class Item : Actuate
{
public virtual string Name { get; set; }
public virtual string Description { get; set; }
public virtual decimal UnitPrice { get; set; }
public virtual ItemStatus Status { get; set; }
public virtual Store Store { get; set; }
}
//Item Mapping class
public class ItemMap : SubclassMap<Item>
{
public ItemMap()
{
Abstract();
Map(x => x.Name);
Map(x => x.Description);
Map(x => x.UnitPrice);
Map(x => x.Status);
References(x => x.Store);
}
}
The entity I have discovered has a problem (other relationship issues might exists)
//Store entity Does not inherit from EntityBase or Actuate
public class Store
{
public virtual int Id { get; set; }
public virtual int Version { get; set; }
public virtual string Name { get; set; }
public virtual IEnumerable<Item> Items { get; set; }
}
//Store mapping class
public class StoreMap : ClassMap<Store>
{
public StoreMap()
{
Id(x => x.Id).GeneratedBy.Assigned();
Version(x => x.Version);
Map(x => x.Name);
HasMany(x => x.Items);
}
}
Problem
If I try to run the following query:
//store = is the Store entity I have retrieved from the database and I am trying
//trying to return the items that are associated with the store and are active
store.Items != null && store.Items.Any(item => item.Status == ItemStatus.Active);
I get the following error:
ERROR
Nhibernate.Exceptions.GenericADOException: could not initialize a collection: [SomeDomain.Store.Items#0][SQL: SELECT items0_.StoreId as StoreId1_, items0_.Id as Id1_, items0_.Id as Id10_0_, items0_.CreatedDate as CreatedD2_10_0_, items0_.ActivatedOn as Activate1_11_0_, items0_.Name as Name12_0_, items0_.Description as Descript2_12_0_, items0_.UnitPrice as UnitPrice12_0_, items0_.Status as Status12_0_, items0_.StoreId as StoreId12_0_ FROM [Item] items0_ WHERE items0_.StoreId=?]"}
Inner Exception
"Invalid object name 'Item'."
Now, if I take out the base classes and Item doesn't inherit, and the
Id, Version
columns are part of the Item entity and are mapped in the ItemMap mapping class (with the ItemMap class inheriting from ClassMap<Item> instead, everything works without issue.
NOTE
I have also attempted to add on the StoreMap class unsuccessful.
HasMany(x => x.Items).KeyColumn("Id");
Any thoughts?
if entityBase is just for inheriting common properties then you do not need to map it at all
public class EntityBaseMap<TEntity> : ClassMap<TEntity> where TEntity : EntityBase
{
public EntityBaseMap()
{
Id(x => x.Id);
Version(x => x.Version);
Map(x => x.CreatedDate);
}
}
public class ActuateMap : EntityBaseMap<Actuate> { ... }
Notes:
Versionmapping should map Version property not Id
Version should be readonly in code so nobody accidently alters it
.KeyColumn("Id") is wrong because the column is from the Items table and then it's both the autogenerated id and foreign key. That's not possible nor usefull
usually only classes which are abstract should containt Abstract() in the mapping
as the title says, I would like to create a many-to-one relationship using Fluent NHibernate. There are GroupEntries, which belong to a Group. The Group itself can have another Group as its parent.
These are my entities:
public class GroupEnty : IGroupEnty
{
public virtual long Id { get; set; }
public virtual string Name { get; set; }
...
public virtual IGroup Group { get; set; }
}
public class Group : IGroup
{
public virtual long Id { get; set; }
public virtual string Name { get; set; }
...
public virtual IGroup Parent { get; set; }
}
And these are the mapping files:
public class GroupEntryMap : ClassMap<GroupEntry>
{
public GroupEntryMap()
{
Table(TableNames.GroupEntry);
Id(x => x.Id).GeneratedBy.Native();
Map(x => x.Name).Not.Nullable();
...
References<Group>(x => x.Group);
}
}
public class GroupMap : ClassMap<Group>
{
public GroupMap()
{
Table(TableNames.Group);
Id(x => x.Id).GeneratedBy.Native();
Map(x => x.Name).Not.Nullable();
...
References<Group>(x => x.Parent);
}
}
With this configuration, Fluent NHibernate creates these tables:
GroupEntry
bigint Id string Name ... bigint Group_id
Group
bigint Id string Name ... bigint Parent_id bigint GroupEntry_id
I don't know why it creates the column "GroupEntry_id" in the "Group" table. I am only mapping the other side of the relation. Is there an error in my configuration or is this a bug?
The fact that "GroupEntry_id" is created with a "not null" constraint gives me a lot of trouble, otherwise I would probably not care.
I'd really appreciate any help on this, it has been bugging me for a while and I cannot find any posts with a similar problem.
Edit: I do NOT want to create a bidirectional association!
If you want a many-to-one where a Group has many Group Entries I would expect your models to look something like this:
public class GroupEntry : IGroupEntry
{
public virtual long Id { get; set; }
public virtual string Name { get; set; }
...
public virtual IGroup Group { get; set; }
}
public class Group : IGroup
{
public virtual long Id { get; set; }
public virtual string Name { get; set; }
...
public virtual IList<GroupEntry> GroupEntries { get; set; }
public virtual IGroup Parent { get; set; }
}
Notice that the Group has a list of its GroupEntry objects. You said:
I don't know why it creates the column "GroupEntry_id" in the "Group" table. I am only mapping the other side of the relation.
You need to map both sides of the relationship, the many side and the one side. Your mappings should look something like:
public GroupEntryMap()
{
Table(TableNames.GroupEntry);
Id(x => x.Id).GeneratedBy.Native();
Map(x => x.Name).Not.Nullable();
...
References<Group>(x => x.Group); //A GroupEntry belongs to one Group
}
}
public class GroupMap : ClassMap<Group>
{
public GroupMap()
{
Table(TableNames.Group);
Id(x => x.Id).GeneratedBy.Native();
Map(x => x.Name).Not.Nullable();
...
References<Group>(x => x.Parent);
//A Group has-many GroupEntry objects
HasMany<GroupEntry>(x => x.GroupEntries);
}
}
Check out the fluent wiki for more examples.
The solution was that I accidentally assigned the same table name for two different entities... Shame on me :(
Thanks a lot for the input though!
I have the following tables in my database:
Announcements:
- AnnouncementID (PK)
- Title
AnouncementsRead (composite PK on AnnouncementID and UserID):
- AnnouncementID (PK)
- UserID (PK)
- DateRead
Users:
- UserID (PK)
- UserName
Usually I'd map the "AnnouncementsRead" using a many-to-many relationship but this table also has an additional "DateRead" field.
So far I have defined the following entities:
public class Announcement
{
public virtual int AnnouncementID { get; set; }
public virtual string Title { get; set; }
public virtual IList<AnnouncementRead> AnnouncementsRead { get; private set; }
public Announcement()
{
AnnouncementsRead = new List<AnnouncementRead>();
}
}
public class AnnouncementRead
{
public virtual Announcement Announcement { get; set; }
public virtual User User { get; set; }
public virtual DateTime DateRead { get; set; }
}
public class User
{
public virtual int UserID { get; set; }
public virtual string UserName { get; set; }
public virtual IList<AnnouncementRead> AnnouncementsRead { get; private set; }
public User()
{
AnnouncementsRead = new List<AnnouncementRead>();
}
}
With the following mappings:
public class AnnouncementMap : ClassMap<Announcement>
{
public AnnouncementMap()
{
Table("Announcements");
Id(x => x.AnnouncementID);
Map(x => x.Title);
HasMany(x => x.AnnouncementsRead)
.Cascade.All();
}
}
public class AnnouncementReadMap : ClassMap<AnnouncementRead>
{
public AnnouncementReadMap()
{
Table("AnnouncementsRead");
CompositeId()
.KeyReference(x => x.Announcement, "AnnouncementID")
.KeyReference(x => x.User, "UserID");
Map(x => x.DateRead);
}
}
public class UserMap : ClassMap<User>
{
public UserMap()
{
Table("Users");
Id(x => x.UserID);
Map(x => x.UserName);
HasMany(x => x.AnnouncementsRead)
.Cascade.All();
}
}
However when I run this I receive the following error:
"composite-id class must override Equals(): Entities.AnnouncementRead"
I'd appreciate it if someone could point me in the right direction. Thanks
You should do just what NHibernate is telling you. AnnouncementRead should override Equals and GetHashCode methods. They should be based on fields that are part of primary key
When implementing equals you should use instanceof to allow comparing with subclasses. If Hibernate lazy loads a one to one or many to one relation, you will have a proxy for the class instead of the plain class. A proxy is a subclass. Comparing the class names would fail.
More technically: You should follow the Liskows Substitution Principle and ignore symmetricity.
The next pitfall is using something like name.equals(that.name) instead of name.equals(that.getName()). The first will fail, if that is a proxy.
http://www.laliluna.de/jpa-hibernate-guide/ch06s06.html
We're using FluentNHibernate and we have run into a problem where our object model requires data from two tables like so:
public class MyModel
{
public virtual int Id { get; set; }
public virtual string Name { get; set; }
public virtual int FooId { get; set; }
public virtual string FooName { get; set; }
}
Where there is a MyModel table that has Id, Name, and FooId as a foreign key into the Foo table. The Foo tables contains Id and FooName.
This problem is very similar to another post here: Nhibernate: join tables and get single column from other table but I am trying to figure out how to do it with FluentNHibernate.
I can make the Id, Name, and FooId very easily..but mapping FooName I am having trouble with. This is my class map:
public class MyModelClassMap : ClassMap<MyModel>
{
public MyModelClassMap()
{
this.Id(a => a.Id).Column("AccountId").GeneratedBy.Identity();
this.Map(a => a.Name);
this.Map(a => a.FooId);
// my attempt to map FooName but it doesn't work
this.Join("Foo", join => join.KeyColumn("FooId").Map(a => a.FooName));
}
}
with that mapping I get this error:
The element 'class' in namespace 'urn:nhibernate-mapping-2.2' has invalid child element 'join' in namespace 'urn:nhibernate-mapping-2.2'. List of possible elements expected: 'joined-subclass, loader, sql-insert, sql-update, sql-delete, filter, resultset, query, sql-query' in namespace 'urn:nhibernate-mapping-2.2'.
any ideas?
I think you misunderstood something here.
Instead of having Id, Name, FooId and FooName in same class you need to create two classes
public class MyModel
{
public virtual int Id { get; set; }
public virtual string Name { get; set; }
public virtual Foo Foo { get; set; }
}
public class Foo
{
public virtual int Id { get; set; }
public virtual string FooName { get; set; }
}
And your mapping classes for these:
public class MyModelMapping : ClassMap<MyModel>
{
public MyModelMapping()
{
this.Id(x => x.Id);
this.Map(x => x.Name);
this.References(x => x.Foo);
}
}
public class FooMapping : ClassMap<Foo>
{
public FooMapping()
{
this.Id(x => x.Id);
this.Map(x => x.FooName);
}
}
this should help.
But remember Convention other Configuration :)