In my project all of entities have composite primary keys [systemId as long, deviceId as long, id as long]. Values filled manualy before I save the entity.
I'm using "code first" approach and to provide simplicity references NHibernate.Mapping.Attributes extension to define schema with attributes just like in Java based Hibernate.
All entities have an abstract base type which provides shared properties and functionality:
[Serializable]
public abstract class EntityBase
{
[CompositeId(0, Name = "id", ClassType = typeof(EntityId))]
[KeyProperty(1, Name = "systemId", Column = "restId")]
[KeyProperty(2, Name = "deviceId", Column = "deviceId")]
[KeyProperty(3, Name = "id", Column = "id")]
private EntityId id = new EntityId(); // this is a component, see below
[Property(Column = "isDeleted", NotNull = true)]
private bool deleted = false;
public EntityId Id
{
get { return id; }
set { id = value; }
}
public bool Deleted
{
get { return deleted; }
set { deleted = value; }
}
}
Behind the composite id there is a component, which represent the complex primary key:
[Serializable]
[Component]
public class EntityId
{
[Property(Column = "restId", NotNull = true)]
private long systemId = 0;
[Property(NotNull = true)]
private long deviceId = 0;
[Property(NotNull = true)]
private long id = 0;
public long SystemId
{
get { return systemId; }
set { systemId = value; }
}
public long DeviceId
{
get { return deviceId; }
set { deviceId = value; }
}
public long Id
{
get { return id; }
set { id = value; }
}
}
I definied two entities called OTMList and OTMItem which have bi-directional OneToMany and ManyToOne associations to each other.
[Serializable]
[Class]
public class OTMList : EntityBase
{
[List(0, Cascade = "none", Generic = true, Lazy = CollectionLazy.True)]
[Key(1, Column = "id")]
[Index(2, Column = "id")]
[OneToMany(3, NotFound = NotFoundMode.Exception, ClassType = typeof(OTMItem))]
private IList<OTMItem> otmItems = new List<OTMItem>();
public IList<OTMItem> OTMItems
{
get { return otmItems; }
set { otmItems = value; }
}
}
[Serializable]
[Class]
public class OTMItem : EntityBase
{
[ManyToOne(0, Name = "otmList", ClassType = typeof(OTMList), Column = "OTMListId", Cascade = "none", Lazy = Laziness.Proxy)]
private OTMList otmList = null;
public OTMList OTMList
{
get { return otmList; }
set { otmList = value; }
}
}
The hibernate mapping xml file contains the following information:
<?xml version="1.0" encoding="utf-8"?>
<hibernate-mapping default-access="field" auto-import="true" assembly="NHibernateTest, Version=1.0.0.0, Culture=neutral, PublicKeyToken=null" xmlns="urn:nhibernate-mapping-2.2">
<class name="NHibernateTest.ListTest.OTM.OTMList, NHibernateTest">
<composite-id class="NHibernateTest.Domain.EntityId, NHibernateTest" name="id">
<key-property name="systemId" column="restId" />
<key-property name="deviceId" column="deviceId" />
<key-property name="id" column="id" />
</composite-id>
<property name="deleted" column="isDeleted" not-null="true" />
<list name="otmItems" lazy="true" cascade="none" generic="true">
<key column="id" />
<index column="id" />
<one-to-many class="NHibernateTest.ListTest.OTM.OTMItem, NHibernateTest" not-found="exception" />
</list>
</class>
<class name="NHibernateTest.ListTest.OTM.OTMItem, NHibernateTest">
<composite-id class="NHibernateTest.Domain.EntityId, NHibernateTest" name="id">
<key-property name="systemId" column="restId" />
<key-property name="deviceId" column="deviceId" />
<key-property name="id" column="id" />
</composite-id>
<property name="deleted" column="isDeleted" not-null="true" />
<many-to-one name="otmList" class="NHibernateTest.ListTest.OTM.OTMList, NHibernateTest" column="OTMListId" cascade="none" lazy="proxy" />
</class>
</hibernate-mapping>
When I validate the schema with SchemaValidator of the NHibernate I get the following exception:
Foreign key (FKF208BF0B9A2FCB3:OTMItem [OTMListId])) must have same number of columns as the referenced primary key (OTMList [restId, deviceId, id])
The problem are the same too when I try to create uni-directional ManyToOne or bi/uni-directional ManyToMany associations.
Somebody can help me please?
The full source code available here:
NHibernateTest source code
The problem is solved, check this out:
http://jzo001.wordpress.com/category/nhibernate/
Related
I have two tables Person and PassportInfo with a structure as given below:
Table Person
(
PersonID uniqueidentifier not null, (PK)
Name varchar(100) not null,
Email varchar(100) not null
)
Table PassportInfo
(
ID int identity(1,1) not null Primary Key,
personID uniqueidentifier null, (FK to PersonID in Person table)
PassportNumber varchar(100) not null
)
Also this is the mapping for Person
<?xml version="1.0" encoding="utf-8" ?>
<hibernate-mapping xmlns="urn:nhibernate-mapping-2.2" assembly="Project" namespace="Project">
<class name="classperson" table="Person" >
<id name="ID" type="System.Guid" column="personID">
<generator class="Guid"/>
</id>
<property name="Name" column="Name" type="System.String" length="100" not-null="true" />
<property name="Email" column="Email" type="System.String" length="100" not-null="true" />
<one-to-one name="classpassportinfo" class="classpassportinfo" constrained="true" />
</class>
</hibernate-mapping>
This is the mapping for PassportInfo
<?xml version="1.0" encoding="utf-8" ?>
<hibernate-mapping xmlns="urn:nhibernate-mapping-2.2" assembly="Project" namespace="Project">
<class name="classpassportinfo" table="PassportInfo" >
<id name="ID" type="System.Int32" column="ID">
<generator class="identity"/>
</id>
<property name="PassportNumber" column="PassportNumber" type="System.String" length="100" not-null="true" />
<one-to-one name="classperson" class="classperson" />
</class>
</hibernate-mapping>
This is the Object Class for Person
namespace Project
{
[Serializable]
public class classperson : Base<System.Guid>
{
private System.String _Name;
private System.String _Email;
private classpassportinfo _classpassportinfo;
public classperson()
{
}
public classperson(System.Guid id)
{
base.ID = id;
}
public virtual System.String Name {
get { return _Name; }
set { _Name = value;}
}
public virtual System.String Email {
get { return _Email; }
set { _Email = value;}
}
public virtual classpassportinfo classpassportinfo {
get { return _classpassportinfo; }
set { _classpassportinfo = value;}
}
}
}
Finally this is the object class for PassportInfo
namespace Project
{
[Serializable]
public class classpassportinfo :Base<Systme.Int32>
{
private System.String _PassportNumber;
private classpassportinfo _classpassportinfo;
public classpassportinfo()
{
}
public classpassportinfo(System.Int32 id)
{
base.ID = id;
}
public virtual System.String PassportNumber {
get { return _PassportNumber; }
set { _PassportNumber = value;}
}
public virtual classperson classperson {
get { return _classperson; }
set { _classperson = value;}
}
}
}
When I execute above code, i am getting and error saying persistent class not known: Project.classpassportinfo. I am new to nhibernate. Any help in this appreciated.
To elaborate and clarify #Fran's comment for anyone else struggling with this problem...
For me, in Visual Studio this issue was resolved by:
Open the solution explorer (Project structure navigator)
Locate the mapping file passportinfo.hbm.xml
Right click and choose properties
Under the advanced tab, make sure "Build Action" is set to "Embedded Resource"
The issue should be resolved now. Good luck
I have used NHibernate for quite some time now but still struggle to do some "simple" stuff. I am trying to work with a many-to-many relationship between my entity ServiceProvider and Features.
Basically every SERVICE_PROVIDERS can have different features which must be present in my table FEATURES.
These are my mapping files:
ServiceProviders.hbm.xml,
<class name="App.Domain.ServiceProvider, App.Domain" table="ServiceProviders">
<id name="Code" type="System.Guid" unsaved-value="00000000-0000-0000-0000-000000000000">
<column name="ServiceProviderCode" />
<generator class="guid.comb" />
</id>
<property name="Description" type="AnsiString">
<column name="Description" length="150" not-null="true" />
</property>
<set name="Features" table="ServiceProvidersFeatures" access="field.pascalcase-underscore" cascade="save-update" optimistic-lock="false">
<key column="ServiceProviderCode"></key>
<many-to-many class="App.Domain.Feature" column="FeatureCode" not-found="exception" />
</set>
</class>
Features,
<class name="App.Domain.Feature, App.Domain" table="Features">
<id name="Code" type="System.Guid" unsaved-value="00000000-0000-0000-0000-000000000000">
<column name="FeatureCode" />
<generator class="guid.comb" />
</id>
<property name="Description" type="AnsiString">
<column name="Description" length="150" not-null="true" />
</property>
<set name="ServiceProviders" table="ServiceProvidersFeatures" cascade="none" inverse="true" lazy="true" access="field.pascalcase-underscore" optimistic-lock="false" mutable="false">
<key column="FeatureCode"></key>
<many-to-many class="App.Domain.ServiceProvider" column="ServiceProviderCode" not-found="ignore" />
</set>
</class>
And these are the 2 main classes:
ServiceProvider.cs
public class ServiceProvider
{
public ServiceProvider()
{
this._Features = new HashSet<Feature>();
}
public virtual Guid Code { get; protected set; }
public virtual string Description { get; set; }
private ICollection<Feature> _Features = null;
public virtual ReadOnlyCollection<Feature> Features
{
get { return (new List<Feature>(_Features).AsReadOnly()); }
}
}
Feature.cs
public class Feature
{
public Feature()
{
this._ServiceProviders = new HashSet<ServiceProvider>();
}
public virtual Guid Code { get; protected set; }
public virtual string Description { get; set; }
private ICollection<ServiceProvider> _ServiceProviders = null;
public virtual ReadOnlyCollection<ServiceProvider> ServiceProviders
{
get { return (new List<ServiceProvider>(_ServiceProviders).AsReadOnly()); }
}
}
What I am trying to do is fetch all the services-providers (with all the features) where the description starts with a certain string, and they have at least one feature specified (param).
I reckon I need a subquery but I don't know how to build the QueryOver. It should be something like this:
var serviceProviders =
session.QueryOver<App.Domain.ServiceProvider>()
.Inner.JoinAlias(x => x.Features, () => features)
.WhereRestrictionOn(f => f.Description).IsLike("%" + "test" + "%")
.AndRestrictionOn(() => features.Code).IsIn(<SubQuery>)
.List();
I've come up with an extension method with allows me to build expressions:
public static class ServiceProviderSearch
{
public static IQueryOver<App.Domain.ServiceProvider, App.Domain.ServiceProvider> AttachWhereForSearchText(this IQueryOver<App.Domain.ServiceProvider, App.Domain.ServiceProvider> mainQuery, string searchText)
{
if (!string.IsNullOrEmpty(searchText))
{
ICriterion filterSearchText = Expression.Disjunction()
.Add(Restrictions.On<App.Domain.ServiceProvider>(f => f.Description).IsLike(searchText, MatchMode.Anywhere))
.Add(Restrictions.On<App.Domain.ServiceProvider>(f => f.ExtendedDescription).IsLike(searchText, MatchMode.Anywhere));
mainQuery.Where(filterSearchText);
}
return (mainQuery);
}
public static IQueryOver<App.Domain.ServiceProvider, App.Domain.ServiceProvider> AttachWhereForFeatures(this IQueryOver<App.Domain.ServiceProvider, App.Domain.ServiceProvider> mainQuery, App.Domain.ServiceProvider serviceProvider, App.Domain.Feature features, Guid[] listOfFeatures)
{
if ((listOfFeatures != null) && (listOfFeatures.Count() > 0))
{
mainQuery
.Inner.JoinAlias(() => serviceProvider.Features, () => features);
mainQuery.WithSubquery.WhereProperty(() => features.Code)
.In(
QueryOver.Of<App.Domain.Feature>()
.WhereRestrictionOn(f => f.Code)
.IsIn(listOfFeatures)
.Select(f => f.Code)
);
}
return (mainQuery);
}
}
So now I can write something like this:
App.Domain.ServiceProvider serviceProvider = null;
App.Domain.Feature features = null;
App.Domain.Language languages = null;
App.Domain.Service services = null;
Guid[] selectedFeatures = {};
var serviceProviders = Session.QueryOver(() => serviceProvider);
serviceProviders
.AttachWhereForSearchText(<searchText>)
.AttachWhereForFeatures(serviceProvider, features, selectedFeatures);
Results = serviceProviders
.TransformUsing(Transformers.DistinctRootEntity)
.Take(<pageSize>)
.Skip((<page> - 1) * <pageSize>)
.ToList<App.Domain.ServiceProvider>();
Inspiration from this answer.
There are couple of things I would change in your snippet. First, you don't need to specify the % in your IsLike method: NHibernate does that automatically.
Second, you can construct the subquery in the following manner:
var subquery =
session.QueryOver<App.Domain.Feature>()
.WhereRestrictionOn(f => f.Description).IsLike("test", MatchMode.Anywhere)
.Select(f => f.Code);
You can plug this in your main query:
var serviceProviders =
session.QueryOver<App.Domain.ServiceProvider>()
.WithSubquery.WhereProperty(s => s.Code).In(subquery)
.List();
Or you can even try:
var serviceProviders =
session.QueryOver<App.Domain.ServiceProvider>()
.JoinQueryOver<App.Domain.Feature>(s => s.Features)
.WhereRestrictionOn(f => f.Description).IsLike("test", MatchMode.Anywhere)
.List<App.Domain.ServiceProvider>();
Depending on your lazy settings, you can then initialize the Features collection with,
serviceProviders.ToList()
.ForEach(service => NHibernateUtil.Initialize(service.Features));
I have created a composite key, and it is working, but ideals I would like the separate directly fields in the row class.
The current way I'm doing this is the following:
private UserPrimaryKey _compositeKey;
public virtual UserPrimaryKey CompositeKey
{
get
{
if (_compositeKey == null) _compositeKey = new UserPrimaryKey();
return _compositeKey;
}
set {
if (_compositeKey == value) return;
_compositeKey = value;
Host = value.Host;
UserAccount = value.User;
}
}
public string Host { get; set; }
public string UserAccount { get; set; }
And i was wondering if there is any better way of doing this? Possibly in NHibernate config file.
My current config file is the follwoing:
<class name="TGS.MySQL.DataBaseObjects.DataBasePrivilege,TGS.MySQL.DataBaseObjects" table="user">
<composite-id name="CompositeKey" class="TGS.MySQL.DataBaseObjects.UserPrimaryKey, TGS.MySQL.DataBaseObjects">
<key-property name="Host" column="Host" type="string" length="60" />
<key-property name="User" column="User" type="string" length="16" />
</composite-id>
</class>
You can create the properties directly in your class... and map them with:
<composite-id>
<key-property name="Host"/>
<key-property name="UserAccount"/>
</composite-id>
If you do that, you'll have to override Equals and GetHashCode in your class.
I would suggest the following:
private UserPrimaryKey _compositeKey;
public virtual UserPrimaryKey CompositeKey
{
get
{
if (_compositeKey == null) _compositeKey = new UserPrimaryKey();
return _compositeKey;
}
set {
if (_compositeKey == value) return;
_compositeKey = value;
Host = value.Host;
UserAccount = value.User;
}
}
public string Host
{
get
{
return CompositeKey.Host;
}
set
{
CompositeKey.Host = value;
}
}
public string UserAccount
{
get
{
return CompositeKey.User;
}
set
{
CompositeKey.User = value;
}
}
This way you dont duplicate data, only return/set the data inside the composite key.
I would avoid the composite key when ever you can. Replace it with a regular unique constraint on both columns:
<class name="DataBasePrivilege" table="user">
<id name="id">
<generator class="hilo">
<param name="table">user_HiLo</param>
<param name="max_lo">100</param>
</generator>
</id>
<property name="Host" length="60" unique-key="user_host"/>
<property name="User" length="16" unique-key="user_host"/>
</class>
(By the way: you don't need to specify types in common cases, and you don't need to specify column names if they match the property names. This keeps you xml readable)
Using Fluent NHibernate, I cannot seem to devise the necessary automapping conventions for the following (seemingly simple and common) use-case:
public class MyClass
{
private int _specialIdentityField
private string _firstname;
public Id { get { return _specialIdentityField; }; }
public virtual string Firstname
{
get
{
return _firstname;
}
set
{
_firstname = value;
}
}
}
public class OtherClass
{
private int _specialIdentityField
private string _lastname;
public Id { get { return _specialIdentityField; }; }
public virtual string Lastname
{
get
{
return _lastname;
}
set
{
_lastname = value;
}
}
}
The desired mappings are like so:
<hibernate-mapping xmlns="urn:nhibernate-mapping-2.2" default-access="field.camelcase-underscore" auto-import="true" default-cascade="none" default-lazy="true">
<class xmlns="urn:nhibernate-mapping-2.2" mutable="true" name="MyClass" table="`MyClass`">
<id name="_specialIdentityField" type="System.Int32" access=field>
<column name="Id" />
<generator class="identity" />
</id>
<property name="Firstname" type="System.String">
<column name="Firstname" />
</property>
</class>
<class xmlns="urn:nhibernate-mapping-2.2" mutable="true" name="OtherClass" table="`OtherClass`">
<id name="_specialIdentityField" type="System.Int32" access=field>
<column name="Id" />
<generator class="identity" />
</id>
<property name="Lastname" type="System.String">
<column name="Lastname" />
</property>
</class>
</hibernate-mapping>
Basically the rules are:
everything is field-camelcase-underscore as an access type EXCEPT identity
identity is a fixed-name field in every class (name=_someSpecialIdentityField)
identity access is always field-only and bears no relation to the name of the RO property that surrounds it
The part of this that is completely tripping me up is the convention-mapping of the identity-related elements (clearly the convention-mapping of the properties is completely standard fare). The issue I am having is how to tell FNH conventions that my identity field is a fixed-name. All of the convention overrides that I can find seem to assume there will always be some relationship between the property that represents identity and the name of its underlying backing field (e.g. I can set a 'custom prefix' for the backing field, but cannot seem to see how I can just say "this is always the name of the backing field").
Its obvious to me how to accomplish this with explicit mapping (and for that matter, with XML mapping files) but not obvious at all to me how to accomplish this with convention-based (Automapping) mapping in FNH.
This can't be an atypical use-case so I must just be overlooking something terribly obvious. Thoughts from any FNH gurus appreciated!
EDIT: Take a look at the IAutomappingConfiguration interface. Create you own implementation or override the DefaultAutomappingConfiguration class.
public virtual bool IsId(Member member)
{
return member.Name.Equals("id", StringComparison.InvariantCultureIgnoreCase);
}
then you add it to the initialization:
Fluently.Configure( Configuration )
.Mappings( cfg =>
{ cfg.AutoMappings.Add( IAutomappingConfigurationInstance )}
===============================================
Hi Steve, I think I know what you are trying to do. I use Proteus and FNH automapping. To do the trick with the id I created a wrapper around Proteus which do two things:
1) Maps the ID
2) Hides the Setter for the id
public abstract class EntityObject<TEntity> : IdentityPersistenceBase<TEntity, Guid>, IEntity
where TEntity : class, IEntity
{
public virtual Guid Id
{
get { return _persistenceId; }
}
Guid IIdentifiedEntity<Guid>.Id
{
get { return _persistenceId; }
set { _persistenceId = value; }
}
public virtual int Version
{
get { return _persistenceVersion; }
set { _persistenceVersion = value; }
}
}
And to avoid the property IsTransient to be persisted + other stuff you can create MappingAlternation:
public class EntityAlteration : IAutoMappingAlteration
{
public void Alter( AutoPersistenceModel model )
{
model.OverrideAll( map =>
{
Type recordType = map.GetType().GetGenericArguments().Single();
if( recordType.BaseType.Name == "EntityObject`1" )
{
Type changeType = typeof( Change<> ).MakeGenericType( recordType );
var change = ( IChange )Activator.CreateInstance( changeType );
change.Go( map );
}
} );
}
}
interface IChange
{
void Go( object mapObject );
}
class Change<TRecord> : IChange where TRecord : EntityObject<TRecord>
{
void IChange.Go( object mapObject )
{
var map = ( AutoMapping<TRecord> )mapObject;
map.Id( x => x.Id ).GeneratedBy.Guid().Access.Property();
map.IgnoreProperty( x => x.IsTransient );
}
}
PS: I am really missing the times when you were active in the online space. It was exciting Summer and Authumn 2 years ago...
I have the following database schema:
http://lh4.ggpht.com/_SDci0Pf3tzU/SdM3XnAmmxI/AAAAAAAAEps/Ie3xW3ZVNfQ/s400/styleerror.png
And this is my mapping file:
<?xml version="1.0" encoding="utf-8" ?>
<hibernate-mapping xmlns="urn:nhibernate-mapping-2.2" namespace="CodeSmithSampel.Generated.BusinessObjects" assembly="CodeSmithSampel">
<class name="CodeSmithSampel.Generated.BusinessObjects.Store, CodeSmithSampel" table="store" lazy="true">
<id name="Id" column="Id">
<generator class="native" />
</id>
<property name="Name" column="Name" />
<bag name="Employees" lazy="true" cascade="all-delete-orphan" inverse="true" >
<key column="Store_id"></key>
<one-to-many class="Employee"></one-to-many>
</bag>
<bag name="Products" table="storeproduct" lazy="true" cascade="all" inverse="true" >
<key column="Store_id"></key>
<many-to-many column="Product_id" class="Product" />
</bag>
</class>
</hibernate-mapping>
And ths is my Store entity class:
public partial class Store : BusinessBase<int>
{
#region Declarations
private string _name = String.Empty;
private IList<Employee> _employees = new List<Employee>();
private IList<Product> _products = new List<Product>();
#endregion
#region Constructors
public Store() { }
#endregion
#region Methods
public override int GetHashCode()
{
System.Text.StringBuilder sb = new System.Text.StringBuilder();
sb.Append(this.GetType().FullName);
sb.Append(_name);
return sb.ToString().GetHashCode();
}
#endregion
#region Properties
public virtual string Name
{
get { return _name; }
set
{
OnNameChanging();
_name = value;
OnNameChanged();
}
}
partial void OnNameChanging();
partial void OnNameChanged();
public virtual IList<Employee> Employees
{
get { return _employees; }
set
{
OnEmployeesChanging();
_employees = value;
OnEmployeesChanged();
}
}
partial void OnEmployeesChanging();
partial void OnEmployeesChanged();
public virtual IList<Product> Products
{
get { return _products; }
set
{
OnProductsChanging();
_products = value;
OnProductsChanged();
}
}
partial void OnProductsChanging();
partial void OnProductsChanged();
#endregion
}
The product class:
public partial class Product : BusinessBase<int>
{
#region Declarations
private float _price = default(Single);
private string _name = null;
private IList<Store> _stores = new List<Store>();
#endregion
#region Constructors
public Product() { }
#endregion
#region Methods
public override int GetHashCode()
{
System.Text.StringBuilder sb = new System.Text.StringBuilder();
sb.Append(this.GetType().FullName);
sb.Append(_price);
sb.Append(_name);
return sb.ToString().GetHashCode();
}
#endregion
#region Properties
public virtual float Price
{
get { return _price; }
set
{
OnPriceChanging();
_price = value;
OnPriceChanged();
}
}
partial void OnPriceChanging();
partial void OnPriceChanged();
public virtual string Name
{
get { return _name; }
set
{
OnNameChanging();
_name = value;
OnNameChanged();
}
}
partial void OnNameChanging();
partial void OnNameChanged();
public virtual IList<Store> Stores
{
get { return _stores; }
set
{
OnStoresChanging();
_stores = value;
OnStoresChanged();
}
}
partial void OnStoresChanging();
partial void OnStoresChanged();
#endregion
}
The mapping for the Product class:
<?xml version="1.0" encoding="utf-8" ?>
<hibernate-mapping xmlns="urn:nhibernate-mapping-2.2" namespace="CodeSmithSampel.Generated.BusinessObjects" assembly="CodeSmithSampel">
<class name="CodeSmithSampel.Generated.BusinessObjects.Product, CodeSmithSampel" table="product" lazy="true">
<id name="Id" column="Id">
<generator class="native" />
</id>
<property name="Price" column="Price" />
<property name="Name" column="Name" />
<bag name="Stores" table="storeproduct" lazy="true" cascade="all" inverse="true" >
<key column="Product_id"></key>
<many-to-many column="Store_id" class="Store" />
</bag>
</class>
</hibernate-mapping>
What is particularly weird is that when I add a Store object to one of the product, the database record is not updated; the add doesn't seem to take place, although the new store object exists in the database:
IManagerFactory managerFactory = new ManagerFactory();
var productManager = managerFactory.GetProductManager();
var myProduct= productManager.GetById(2);
var myStore = new Store();
myStore.Name = "new Store"; //a "new store" entry is created in the Store table
myProduct.Stores.Add(myStore); // but this "new store" is not linked to the myproduct, as it should.
productManager.Session.CommitChanges();
Is there anything I miss?
Note: I generate the above code using CodeSmith.
Edit: The accepted answer works. The reason I got in this problem is because
Only one entity class should have inverse = true, not two. So either Product or Store should set the inverse to false. The code generation tool didn't handle this properly.
The correct way to Add Many to Many relationship is explained below. You must add two times.
Can this have anything to do with the fact that you have a surrogate key in the storeproducts table ?
What happens if you remove this surrogate key column Id, and put the primary key on the combination of the product_id and store_id columns ?
I believe that, if you want to have a surrogate key on the storeproducts table, you'll have to create yet another entity.
If you want to use the surrogate key, you'll have to use the idbag mapping.
How does your Product class and mapping look like ?
I see that you specify the 'inverse' attribute in your mapping of the Products collection in the Store entity.
If you do this (and thus you have a bi-directional association), then you should add the Store to the Stores collection of the product as well.
Since -from the NH documentation- :
Changes made only to the inverse end
of the association are not persisted.
This means that NHibernate has two
representations in memory for every
bidirectional association, one link
from A to B and another link from B to
A. This is easier to understand if you
think about the .NET object model and
how we create a many-to-many
relationship in C#:
category.Items.Add(item); // The category now "knows" about the relationship
item.Categories.Add(category); // The item now "knows" about the relationship
session.Update(item); // No effect, nothing will be saved!
session.Update(category); // The relationship will be saved
The non-inverse side is used to save
the in-memory representation to the
database. We would get an unneccessary
INSERT/UPDATE and probably even a
foreign key violation if both would
trigger changes! The same is of course
also true for bidirectional
one-to-many associations.
You may map a bidirectional
one-to-many association by mapping a
one-to-many association to the same
table column(s) as a many-to-one
association and declaring the
many-valued end inverse="true".
This means, that only one of the ends should be inverse.
Adding a Product to a store, should be done like this:
public class Store
{
public void AddProduct( Product p )
{
if( _products.Contains (p) == false )
{
_products.Add (p);
p.AddStore(this);
}
}
}
public class Product
{
public void AddStore( Store s )
{
if( _stores.Contains (s) == false )
{
_stores.Add (s);
s.AddProduct(this);
}
}
}
(Very important to check whether the collection already contains the item to be added; otherwise you'll end up in an infinite loop.