<class name="CashThreshold" table="CASH_THRESHOLD_COUNTERS" lazy="true" >
<id name="Id" column="ID" >
<generator class="assigned" />
</id>
<bag name="ThresholdNominalsList" cascade="all" inverse="true" lazy="false" table="CASH_THRESHOLD_CAS_COUNTERS">
<key column="CASH_THRESHOLD_ID" />
<one-to-many class="NominalThreshold" />
</bag>
Map second table
<class name="NominalThreshold" table="CASH_THRESHOLD_CAS_COUNTERS" lazy="true" >
<composite-id>
<key-property name="CashTrasholdId" column="CASH_THRESHOLD_ID" type="long"></key-property>
<key-property name="Nominal" column="NOMINAL" type="long"></key-property>
</composite-id>
<property name="MinNoteCount" column="MIN_NOTE_COUNT" />
<property name="MaxNoteCount" column="MAX_NOTE_COUNT" />
Table classes
public class CashThreshold : ICashThreshold
{
public virtual long Id { set; get; }
/// !!!!!!! IS ALWAYS AMPTY, but not null !!!!!
public virtual IList<INominalThreshold> ThresholdNominalsList { set; get; }
}
public class NominalThreshold : INominalThreshold
{
public virtual long CashTrasholdId { set; get; }
public virtual long Nominal { set; get; }
public virtual long MinNoteCount { set; get; }
public virtual long MaxNoteCount { set; get; }
public override bool Equals(Object obj)
{
var tmp = (INominalThreshold)obj;
return (tmp.CashTrasholdId == CashTrasholdId && tmp.Nominal == Nominal);
}
public override int GetHashCode()
{
return (int)CashTrasholdId ^ (int)Nominal;
}
}
Function for getting list of ICashThreshold
ICriteria selectAll = currentSession.CreateCriteria<ICashThreshold>();
IList<ICashThreshold> list = selectAll.List<ICashThreshold>();
Query executed whith no errors. Bag-query executed successfully in sql-client and returned 4 result, but IList< INominalThreshold > ThresholdNominalsList has no elements.
Thanks.
Problem solved. NHibernate mapped bag successfully, but list was empty, because the data in DB was NOT COMMITTED. I inserted test data in the table, but did not commit it. When I execute query in sql-client, it executed successfully(because do it in session, where table rows inserted), but hibernate had another session. Thats why NHibernate could not see the table data.
Related
Problem encountered
When I create a transient instance with a children collection, everything gets persisted.
Aside, if I update an instance of one of the children object, it doesn't get updated when I save the parent object.
I'm actually using cascade="all"
Problem reproduction
The problem occurs when I have loaded all of my Customer occurences, and I change an invoice, though I always use the same ISession.
var repository = new CustomerRepository(session);
var customers = repository.GetAll();
var customer = customers.Where(c => c.Name == "Stack Overflow").FirstOrDefault();
customer.Invoices
.Where(i => i.Number == "1234")
.Approve(WindowsIdentity.GetCurrent().Name);
repository.Save(customer);
Step by step debugging clearly shows the repository.Save() method being executed, and the changes won't show inte the underlying database.
An update directly against the database table is possible, so no contraint causing the update to fail on the database-side.
Herewith some code in case it might help.
Customer.hbm.xml
<hibernate-mapping xmlns="urn:nhibernate-mapping-2.2"
namespace="MyProject.Model"
assembly="MyProject">
<class name="Customer" table="AC_CUST" schema="AC">
<id name="Id" column="AC_CUST_ID" type="Int32" unsaved-value="0">
<generator class="sequence-identity">
<param name="sequence">AC_CUST_ID_SEQ</param>
<param name="schema">AC</param>
</generator>
</id>
<property name="Name" column="AC_CUST_NAME" type="String"
not-null="true" />
<property name="PhoneNumber" column="AC_CUST_PHNUM" type="Int64"
not-null="true" />
<bag name="Invoices" table="ESO_RAPP_ACCES_INFO_DSQ" schema="AC"
fetch="join" lazy="true" inverse="true" cascade="all">
<key column="AC_CUST_ID" foreign-key="AC_CUST_INV_FK" />
<one-to-many class="Invoice" />
</bag>
</class>
</hibernate-mapping>
Customer
public class Customer {
public Customer() { Invoices = new List<Invoice>(); }
public virtual int Id { get; proected set; }
public virtual IList<Invoice> Invoices { get; protected set; }
public virtual string Name { get; set; }
public virtual string PhoneNumber { get; set; }
}
Invoice.hbm.xml
<hibernate-mapping xmlns="urn:nhibernate-mapping-2.2"
namespace="MyProject.Model"
assembly="MyProject">
<class name="Invoice" table="AC_INV" schema="AC">
<id name="Id" column="AC_INV_ID" type="Int32" unsaved-value="0">
<generator class="sequence-identity">
<param name="sequence">AC_INV_ID_SEQ</param>
<param name="schema">AC</param>
</generator>
</id>
<property name="Approved" column="AC_INV_APPRD" type="DateTime"
not-null="false" />
<property name="Approver" column="AC_INV_APPRR" type="String" length="15"
not-null="false" />
<property name="Number" column="AC_INV_NUMBR" type="String" length="15"
not-null="true" />
<property name="Produced" column="AC_INV_PROD" type="DateTime"
not-null="false" />
<many-to-one class="Customer" column="AC_CUST_ID" />
</class>
</hibernate-mapping>
Invoice
public class Invoice {
public Invoice() {
Items = new List<Item>();
Produced = DateTime.Now;
}
public virtual DateTime? Approved { get; protected set; }
public virtual string Approver { get; protected set; }
public virtual Customer Customer { get; set; }
public virtual int Id { get; proected set; }
public virtual string Number { get; set; }
public virtual DateTime? Produced { get; set; }
public virtual void Approve(string approver) {
Approved = DateTime.Now;
Approver = approver;
}
public virtual void Reject() { Produced = null; }
}
CustomerRepository
public class CustomerRepository {
public CustomerRepository(ISession session) { Session = session; }
public ISession Session { get; protected set; }
public Customer Save(Customer instance) {
Session.SaveOrUpdate(instance);
return Instance;
}
}
Related articles
nHibernate one-to-many inserts but doesnt update
NHibernate - code example for update
Any help appreciated.
Don't forget to Flush() your session!
NHibernate keeps track of all the changes along a session lifecycle which should only live for a form (Desktop) or a page (Web).
Because of the session is aware of all the changes, it doesn't necessarily commit the changes to the underlying database. Instead, it keeps a record of all the changes into a dictionary, then when it is flushed by calling ISession.Flush(), you actually demand the session to commit the changes for good.
So solution shall be:
repository.Save(customer);
session.Flush();
Or you may as well code a Commit() method within your repository which would Flush() the session upon a call.
repository.Save(customer);
repository.Commit();
And your repository would look like:
// Assuming you stock your session in the `Session` property.
public void Commit() { Session.Flush(); }
That's all!
Take the following entities:
public class Company : Entity<Guid>
{
public virtual string Name { get; set; }
public virtual IList<IEmployee> Employees { get; set; }
public Company()
{
Id = Guid.NewGuid();
Employees = new List<IEmployee>();
}
}
public interface IEmployee
{
Guid? Id { get; set; }
string Name { get; set; }
void Work();
Company Company { get; set; }
}
public class ProductionEmployee : Entity<Guid>, IEmployee
{
public virtual string Name { get; set; }
public virtual Company Company { get; set; }
public ProductionEmployee()
{
Id = Guid.NewGuid();
}
public virtual void Work()
{
Console.WriteLine("I'm making the stuff.");
}
}
public class SalesEmployee : Entity<Guid>, IEmployee
{
public virtual string Name { get; set; }
public virtual Company Company { get; set; }
public SalesEmployee()
{
Id = Guid.NewGuid();
}
public virtual void Work()
{
Console.WriteLine("I'm selling the stuff.");
}
}
Mapped in the following way in NHibernate:
<hibernate-mapping xmlns="urn:nhibernate-mapping-2.2"
namespace="PolymorphicUnionSubclass.Domain.Entities"
assembly="PolymorphicUnionSubclass.Domain">
<class name="Company" table="`Company`">
<id name="Id" column="Id" type="guid">
<generator class="assigned"/>
</id>
<property name="Name" column="`Name`"/>
<bag name="Employees" inverse="true" cascade="save-update">
<key column="CompanyId"></key>
<one-to-many class="IEmployee" />
</bag>
</class>
</hibernate-mapping>
<hibernate-mapping xmlns="urn:nhibernate-mapping-2.2"
namespace="PolymorphicUnionSubclass.Domain.Entities"
assembly="PolymorphicUnionSubclass.Domain">
<class name="IEmployee" abstract="true">
<id name="Id" column="Id" type="guid">
<generator class="assigned"/>
</id>
<many-to-one name="Company" column="`CompanyId`" cascade="save-update"/>
<union-subclass name="ProductionEmployee" table ="`ProductionEmployee`" >
</union-subclass>
<union-subclass name="SalesEmployee" table ="`SalesEmployee`">
</union-subclass>
</class>
</hibernate-mapping>
If I create a Company entity and add IEmployee entities to its collection (also setting the Company property of the IEmployee entity to create the bi-directional relationship), Then when I save the company, everything goes into the database as expected. The companyId is set correctly on the PoductionEmployee and SalesEmlpoyee records.
But when I come to load it, I get the following error:
The column 'CompanyId' was specified multiple times for 'employees0_'
The generated SQL looks like this:
SELECT employees0_.CompanyId as CompanyId1_, employees0_.Id as Id1_, employees0_.Id as Id9_0_, employees0_.[CompanyId] as CompanyId2_9_0_, employees0_.clazz_ as clazz_0_
FROM ( select Id, CompanyId, CompanyId, 1 as clazz_ from [ProductionEmployee] union all select Id, CompanyId, CompanyId, 2 as clazz_ from [SalesEmployee] ) employees0_
WHERE employees0_.CompanyId=?
Why is it generating the CopmanyId column twice and how do I prevent this?
Nothing to do with union-subclass in the end. The problem was in the one-to-many collection I had specified column="CompanyId", and in the many-to-one I had specified column="`CompanyId`". Including the backticks in one and not the other had caused NHibernate to think they were different column. Never come across this in all my time using NHibernate.
I have the following mapping
UserProfile.hbm.xml
<?xml version="1.0" encoding="utf-8" ?>
<hibernate-mapping xmlns="urn:nhibernate-mapping-2.2"
assembly="AngusBook.Domain"
namespace="AngusBook.Domain">
<class name="UserProfile">
<id name="UserId" type="int">
<generator class="identity" />
</id>
<natural-id mutable="false">
<property name="UserName" />
</natural-id>
<set name="Companies" table="Users_Companies">
<key column="UserId"/>
<many-to-many column="CompanyId" class="Company" />
</set>
</class>
</hibernate-mapping>
Company.hbm.xml
<?xml version="1.0" encoding="utf-8" ?>
<hibernate-mapping xmlns="urn:nhibernate-mapping-2.2" assembly="AngusBook.Domain" namespace="AngusBook.Domain" >
<class name="Company">
<id name="Id">
<generator class="hilo" />
</id>
<natural-id mutable="false">
<property name="CompanyName" />
</natural-id>
<set name="Users" table="Users_Companies">
<key column="CompanyId"/>
<many-to-many column="UserId" class="UserProfile" />
</set>
</class>
</hibernate-mapping>
Table design
With this mapping I have, I can have two identical rows in Users_Companies table (ie: two rows with the same pair of foreign keys that belong to the UserProfile and Company table). Using mappings, how do I cause NHibernate or SQL to throw an error/exception when an attempt is made to insert a pair of foreign keys into Users_Companies that already exist in the table? I would like each row in Users_Companies to be unique and not have repetitive data.
I found out the problem. I didn't implement the Equals() and GetHashCode() correctly.
I ended up refactored my entities to use the following base entity class and that fixed the issue. No error is thrown when a duplicated entity is added to the set but the set will simply not add the duplicated entity.
Entity.cs
public abstract class Entity
{
public virtual TId Id { get; protected set; }
protected virtual int Version { get; set; }
public override bool Equals(object obj)
{
return Equals(obj as Entity<TId>);
}
private static bool IsTransient(Entity<TId> obj)
{
return obj != null &&
Equals(obj.Id, default(TId));
}
private Type GetUnproxiedType()
{
return GetType();
}
public virtual bool Equals(Entity<TId> other)
{
if (other == null)
return false;
if (ReferenceEquals(this, other))
return true;
if (!IsTransient(this) &&
!IsTransient(other) &&
Equals(Id, other.Id))
{
var otherType = other.GetUnproxiedType();
var thisType = GetUnproxiedType();
return thisType.IsAssignableFrom(otherType) ||
otherType.IsAssignableFrom(thisType);
}
return false;
}
public override int GetHashCode()
{
if (Equals(Id, default(TId)))
return base.GetHashCode();
return Id.GetHashCode();
}
}
public abstract class Entity : Entity<Guid>
{
}
UserProfile.cs
public class UserProfile : Entity<int>
{
public UserProfile()
{
Companies = new HashedSet<Company>();
}
public virtual string UserName { set; get; }
public virtual ISet<Company> Companies { set; get; }
}
Company.cs
public class Company : Entity<int>
{
public Company()
{
Users = new HashedSet<UserProfile>();
}
public Company(string name) :this()
{
this.CompanyName = name;
}
public virtual string CompanyName { set; get; }
public virtual ISet<UserProfile> Users { set; get; }
}
I am trying to map Users to each other. The senario is that users can have buddies, so it links to itself
I was thinking of this
public class User
{
public virtual Guid Id { get; set; }
public virtual string FirstName { get; set; }
public virtual string LastName { get; set; }
public virtual string EmailAddress { get; set; }
public virtual string Password { get; set; }
public virtual DateTime? DateCreated { get; set; }
**public virtual IList<User> Friends { get; set; }**
public virtual bool Deleted { get; set; }
}
But am strugling to do the xml mapping.
<?xml version="1.0" encoding="utf-8" ?>
<hibernate-mapping xmlns="urn:nhibernate-mapping-2.2"
assembly="MyVerse.Domain"
namespace="MyVerse.Domain" >
<class name="User" table="[User]">
<id name="Id">
<generator class="guid" />
</id>
<property name="FirstName" />
<property name="LastName" />
<property name="EmailAddress" />
<property name="Password" />
<property name="DateCreated" />
<property name="Deleted" />
<set name="Friends" table="UserFriend">
<key foreign-key="Id"></key>
<many-to-many class="User"></many-to-many>
</set>
</class>
</hibernate-mapping>
something like
<bag name="Friends" table="assoc_user_table" inverse="true" lazy="true" cascade="all">
<key column="friend_id" />
<many-to-many class="User,user_table" column="user_id" />
</bag>
Consider using the repository pattern. Create a Repository contract and a base abstract class that takes one of your entities as a type (your mapped class)
Open the session when the repository is initialized and close when destroyed. (implement IDisposable).
Then make sure all of your access to the session happens within the using statement:
[pseudo-code]:
using(var repository = RepositoryFactory<EntityType>.CreateRepository())
{
var entity = repository.get(EntityID);
foreach (somesubclass in entity.subclasscollection)
{
//Lazy loading can happen here, session is still open with the repository
... Do Something
}
}
I use a base abstract class for my Repositories. This one is for my readonly repository but you'll get the drift. They key is to keep your units of work small, open the session only when you have something to do with the database, then let it close on the dispose. Here's the base class, disclaimer YMMV:
public interface IEntity
{
int Id { get; set; }
}
public interface IRORepository<TEntity> : IDisposable where TEntity : IEntity
{
List<TEntity> GetAll();
TEntity Get(int id);
}
public abstract class RORepositoryBase<T> : IRORepository<T> where T : IEntity
{
protected ISession NHibernateSession;
protected RORepositoryBase()
{
NHibernateSession = HibernateFactory.OpenSession();
NHibernateSession.DefaultReadOnly = true;
}
public ISession Session { get { return NHibernateSession; } }
public void Dispose()
{
NHibernateSession.Flush();
NHibernateSession.Close();
NHibernateSession.Dispose();
}
public virtual List<T> GetAll()
{
return NHibernateSession.Query<T>().ToList();
}
public virtual T Get(int id)
{
return NHibernateSession.Get<T>(id);
}
}
I am in the process or learning NHibernate so bear with me.
I have an Order class and a Transaction class. Order has a one to many association with transaction. The transaction table in my database has a not null constraint on the OrderId foreign key.
Order class:
public class Order {
public virtual Guid Id { get; set; }
public virtual DateTime CreatedOn { get; set; }
public virtual decimal Total { get; set; }
public virtual ICollection<Transaction> Transactions { get; set; }
public Order() {
Transactions = new HashSet<Transaction>();
}
}
Order Mapping:
<class name="Order" table="Orders">
<cache usage="read-write"/>
<id name="Id">
<generator class="guid"/>
</id>
<property name="CreatedOn" type="datetime"/>
<property name="Total" type="decimal"/>
<set name="Transactions" table="Transactions" lazy="false" inverse="true">
<key column="OrderId"/>
<one-to-many class="Transaction"/>
</set>
Transaction Class:
public class Transaction {
public virtual Guid Id { get; set; }
public virtual DateTime ExecutedOn { get; set; }
public virtual bool Success { get; set; }
public virtual Order Order { get; set; }
}
Transaction Mapping:
<class name="Transaction" table="Transactions">
<cache usage="read-write"/>
<id name="Id" column="Id" type="Guid">
<generator class="guid"/>
</id>
<property name="ExecutedOn" type="datetime"/>
<property name="Success" type="bool"/>
<many-to-one name="Order" class="Order" column="OrderId" not-null="true"/>
Really I don't want a bidirectional association. There is no need for my transaction objects to reference their order object directly (I just need to access the transactions of an order). However, I had to add this so that Order.Transactions is persisted to the database:
Repository:
public void Update(Order entity)
{
using (ISession session = NHibernateHelper.OpenSession()) {
using (ITransaction transaction = session.BeginTransaction()) {
session.Update(entity);
foreach (var tx in entity.Transactions) {
tx.Order = entity;
session.SaveOrUpdate(tx);
}
transaction.Commit();
}
}
}
My problem is that this will then issue an update for every transaction on the order collection (regardless of whether it has changed or not).
What I was trying to get around was having to explicitly save the transaction before saving the order and instead just add the transactions to the order and then save the order:
public void Can_add_transaction_to_existing_order()
{
var orderRepo = new OrderRepository();
var order = orderRepo.GetById(new Guid("aa3b5d04-c5c8-4ad9-9b3e-9ce73e488a9f"));
Transaction tx = new Transaction();
tx.ExecutedOn = DateTime.Now;
tx.Success = true;
order.Transactions.Add(tx);
orderRepo.Update(order);
}
Although I have found quite a few articles covering the set up of a one-to-many association, most of these discuss retrieving of data and not persisting back.
Many thanks,
Ben
You need to set the cascade attribute on your mapping so that persistence is cascaded to the child objects:
<set name="Transactions" table="Transactions" lazy="false" inverse="true" cascade="all-delete-orphan">
Your Order object should have an AddTransaction method that sets the parent reference on the child. Something like:
public void AddTransaction(Transaction txn)
{
txn.Order = this;
Transactions.Add(txn);
}
This will cause the Transaction object to be persisted when the Order is persisted. You can expose the Order property on Transaction with the internal modifier so that it's not publicly visible.