I'm discovering nhibernate right now. Thus my question is maybe very stupid :)
What I'm trying to do (I'm working with a legacy database) is to get an entity which some of its data are coming from a table value function.
My entity is the following
public class Entity
{
public virtual int Id { get; protected set; }
....
public virtual int AccessRightId { get; set; }
}
where AccessRightId comes from the table value function (fp_AccessRight('userId'))
I have the following mapping
public class EntityMap : ClassMap<Entity>
{
public EntityMap ()
{
this.Id(entity => entity .Id);
this.Join(
"fp_AccessRight('userId')",
join =>
{
join.Fetch.Join();
join.KeyColumn("EntityId");
join.Map(t => t.AccessRightId, "AccessRightType");
join.Table();
});
}
}
Unfortunately, I'm not able to substitute 'userId' by any value.
Thanks.
Is there a way to do it?
I finally solved it.
The trick was to make the join like this :
this.Join("fp_ACCOUNT_ACL(:AclFilter.userId)"
and then simpley to enable the filter
this.session.EnableFilter("AclFilter").SetParameter("userId", "bdd#5");
I found an example here.
Related
I try to implement 1..0 relations with Entity Framework 6. I use instance associsaltion. I try to repeat the examples from web and forums but somehow it doesn't work for me. Please, help.
Entities:
public class CustomerWithFk : Item // Item contains Id
{
public string Name { get; protected set; }
public virtual City City { get; set; } // relation property. Can be 1 or 0
public virtual Product Product { get; set; }
public decimal Money { get; protected set; }
}
public class City : Item
{
public string Name { get; protected set; }
}
Mappings:
public CityMap()
{
ToTable("Cities");
HasKey(c => c.Id);
}
public CustomerFkAssosiationMap()
{
ToTable("Customers");
HasKey(c => c.Id);
HasRequired(g => g.City)
.WithRequiredDependent();
HasRequired(g => g.Product)
.WithRequiredDependent()
.Map(x => x.MapKey("ProductId"));
}
Database tables:
SQL Profiler gives me enxt SQL request:
SELECT
1 AS [C1],
[Extent1].[Id] AS [Id],
[Extent1].[Name] AS [Name],
[Extent1].[Money] AS [Money],
[Extent1].[CityId] AS [CityId],
[Extent1].[ProductId] AS [ProductId]
FROM [dbo].[Customers] AS [Extent1]
So, I don't see any joins here to load data from Cities or Products.
And the result is Null:
I tried different mapping options, like: HasOptional, WithRequiredPrincipal, tried to add Customers proeprty to City (while it's incorrect and City doesn't have to know something about customers)
Nothing helps. The assosiated entities are always null.
Where am I wrong?
The problem is that you are not including the related objects. Try something like this using Include:
var list = context.CustomerWithFk
.Include("City")
.Include("Product");
That tells Entity Framework that you want to pull back the customer along with the city and product. Here is some further reading if you are interested: http://msdn.microsoft.com/en-us/data/jj574232.aspx.
EDIT: You could also enable lazy loading (based on your comment I believe it is what you are after) by adding this to your context:
context.ContextOptions.LazyLoadingEnabled = true;
Read more about lazy loading here: http://msdn.microsoft.com/en-us/library/vstudio/dd456846(v=vs.100).aspx.
I've scoured Google and SO but haven't come across anyone having the same problem. Here is my model:
public class Hierarchy
{
public virtual Event Prerequisite { get; set; }
public virtual Event Dependent { get; set; }
public override bool Equals(object obj)
{
var other = obj as Hierarchy;
if (other == null)
{
return false;
}
else
{
return this.Prerequisite == other.Prerequisite && this.Dependent == other.Dependent;
}
}
public override int GetHashCode()
{
return (Prerequisite.Id.ToString() + "|" + Dependent.Id.ToString()).GetHashCode();
}
}
Here is my mapping:
public class HierarchyMap : ClassMap<Hierarchy>
{
public HierarchyMap()
{
CompositeId()
.KeyReference(h => h.Prerequisite, "PrerequisiteId")
.KeyReference(h => h.Dependent, "DependentId");
}
}
And here is the ever present result:
{"The entity 'Hierarchy' doesn't have an Id mapped. Use the Id method to map your identity property. For example: Id(x => x.Id)."}
Is there some special configuration I need to do to enable composite id's? I have the latest FNh (as of 6/29/2012).
Edit
I consider the question open even though I've decided to map an Id and reference the 2 Event's instead of using a CompositeId. Feel free to propose an answer.
I figured out this was due to auto mapping trying to auto map the ID
Even though i had an actual map for my class - it still tried to auto map the ID. Once i excluded the class from auto mapping, it worked just fine.
Imagine a database table that looks like this:
create table [dbo].[user]
(
id int IDENTITY(1,1),
username varchar(50) NOT NULL,
firstname varchar(20) NOT NULL,
lastname varchar(30) NOT NULL,
currentid int NULL,
processedby varchar(50) NOT NULL,
processeddate varchar(50) NOT NULL
processedaction varchar(50) NOT NULL
)
What I want to do is to setup NHibernate to load it into my user object, but I only want the current version of the object "user" to be brought back. I know how to do a SQL select to do this on my own, and I feel as if there's something in nHibernate with the usage of triggers and event listeners, but can anyone tell me how to implement the nHibernate repository so I can:
{Repository}.GetCurrent(id) <- pass it any of the ids that are assigned to any of the historical or the current record, and get back the current object.
{Repository}.Save(user) <- I want to always insert the changes to a new row, and then update the old versions to link back to the new id.
Edit
So, there's some confusion here, and maybe I explained it wrong... What I'm trying to do is this, in regards to always getting the current record back...
Select uc.*
FROM User uo
JOIN User uc on uo.currentid=uc.id
WHERE uo.id==:id
But, I don't want to expose "CurrentID" to my object model, since it has no bearing on the rest of the system, IMHO. In the above SQL statement, uo is considered the "original" object set, and uc is considered the current object in the system.
Edit #2:
Looking at this as a possible solution.
http://ayende.com/blog/4196/append-only-models-with-nhibernate
I'm honestly being pigheaded, as I'm thinking about this backward. In this way of running a database, the autoincrementing field should be the version field, and the "id" field should be whatever the autoincrementer's value has at the time of the initial insert.
Answer:
I don't want to take #Firo's fury, and I'm not going to remove it from him, as he took me down the right path... what I wound up with was:
Created a base generic class with two types given
a. type of the object's "ID"
b. type of the object itself.
instantiate all classes.
create a generic interface IRepository class with a type of the object to store/retrieve.
create an abstract generic class with a type of the object to store/retrieve.
create a concrete implementation class for each type to store/retrieve.
inside of the create/update, the procedure looks like:
Type Commit(Type item)
{
var clone = item.DeepClone();
_Session.Evict(item);
clone.Id = 0;
clone.ProcessedDate = DateTime.Now;
if (clone.Action.HasValue)
{
if (clone.Action == ProcessedAction.Create)
clone.Action = ProcessedAction.Update;
}
else
{
clone.Action = ProcessedAction.Create;
}
clone.ProcessedBy = UserRepos.Where(u => u.Username == System.Threading.Thread.CurrentPrincipal.Identity.Name).First().Current;
var savedItem = (_Session.Merge(clone) as Type);
_Session.CreateQuery("UPDATE Type SET CurrentID = :newID where ID=:newID OR CurrentID=:oldID")
.SetParameter("newID", savedItem.Id)
.SetParameter("oldID", item.Id)
.ExecuteUpdate();
return savedItem;
}
In the delete method, we simply update the {object}.Action = ProcessedAction.Delete
I wanted to do this another way, but realizing we need to eventually do historical comparisons, we weren't able to ask nHibernate to filter the deleted objects, as the users will want to see that. We'll create a business facade to take care of the deleted records.
Again, much thanks to #Firo for his help with this.
So, with all that, I can finally do this:
var result = {Repository}.Where(obj => obj.Id == {objectID from caller}).FirstOrDefault();
if (result != null)
{
return result.Current;
}
else
{
return null;
}
and always get my current object back for any requesting ID. Hope it helps someone that is in my situation.
in mapping if you use FluentNHibernate
public UserMap : ClassMap<User>
{
public UserMap()
{
Where("id = currentid"); // always bring back the most recent
}
}
// in Userrepository
public void Update(User user)
{
var clone = user.Clone();
session.Evict(user); // to prevent flushing the changes
var newId = session.Save(clone);
session.CreateQuery("UPDATE User u SET u.currentid = :current") // <-- hql
.SetParameter("current", newId)
.ExecuteUpdate();
}
objectgraphs are a lot trickier with this simple code. I would then do one of the following:
use NHibernate.Envers to store auditing information for me
explicitly creating new entities in BL code
i once saw an append-only-model doing something like the following
// UserBase is there to ensure that all others referencing the User doesnt have to update because user properties changed
class UserBase
{
public virtual int Id { get; set; }
public virtual ICollection<PersonDetails> AllDetails { get; private set; }
public virtual PersonDetails CurrentDetails
{
get { return _currentDetauils; }
set { _currentDetauils = value; AllDetails.Add(value); }
}
// same as above
public virtual ICollection<ConfigDetails> AllConfigs { get; set; }
}
class Order
{
public virtual int Id { get; set; }
public virtual UserBase User { get; set; }
public virtual IList<OrderDetail> AllDetails { get; private set; }
public virtual IList<OrderDetail> ActiveDetails { get; private set; }
public virtual void Add(OrderDetail detail)
{
AllDetails.Add(detail);
ActiveDetails.Add(detail);
}
public virtual void Delete(OrderDetail detail)
{
detail.Active = false;
ActiveDetails.Remove(detail);
}
}
class OrderDetail
{
public virtual int Id { get; set; }
public virtual Order Parent { get; set; }
public virtual bool Active { get; set; }
}
class OrderMap : ClassMap<Order>
{
public OrderMap()
{
HasMany(o => o.AllDetails);
HasMany(o => o.ActiveDetails).Where("active=1");
}
}
// somewhere
public void UpdateTaxCharge(OrderDetail detail, TaxCharge charge)
{
var clone = detail.Clone();
clone.TaxCharge = charge;
detail.Order.Delete(detail);
detail.Order.Add(clone);
}
You can tell NHibernate what exactly SQL it should generate when persisting and loading an entity. For example you can tell NHibernate to use a stored procedure instead of a plain SQL statement. If this is an option for you I can farther elaborate my answer.
I have a situation where my primary key is a char(2) in SqlServer 2008, and I want to reference it in a one-to-many relationship, but the ManyToOneBuilder (which is returned by ClassMap<>.References()) doesn't have a CustomSqlType() method. Specifically:
public class State
{
// state FIPS code is 2 characters
public virtual string StateCode { get; set; }
public virtual ICollection<County> { get; set; }
}
public class County
{
// state-county FIPS code is 5 characters
public virtual string StateCountyCode { get; set; }
public virtual State State { get; set; }
}
public class StateMap : ClassMap<State>
{
public StateMap()
{
Id(e => e.StateCode).CustomSqlType("char(2)").GeneratedBy.Assigned();
}
}
public class CountyMap : ClassMap<County>
{
public CountyMap()
{
Id(e => e.StateCountyCode).CustomSqlType("char(5)").GeneratedBy.Assigned();
References(e => e.State, "StateCode")
// Here's what I want to do, but can't because the method is not
// implemented on the class ManyToOneBuilder:
.CustomSqlType("char(2)");
}
}
Is there any way to accomplish this without modifying the ManyToOneBuilder? Is there a way to automatically map the FK (i.e. County.StateCode) to the correct type? It's trivial to add CustomSqlType to ManyToOneBuilder, but is that the right thing to do?
Keep your mapping definition as is, add your "State" column definition with
.CustomSqlType("char(2)")
and set for this column Insert=false and update=false.
I've the same problem and in AutoMapping I use this code:
mapping.Map(x => x.IdUniArticolo)
.CustomSqlType("varchar(50)")
.Not.Insert().Not.Update();
mapping.References(x => x.Articolo)
.Column("IdUniArticolo").PropertyRef("IdUniArticolo");
Keep in mind that if NHibernate itself doesn't support it, then Fluent NHibernate can't, and I don't NHibernate supports the scenario you have. I had a similar problem in that I had a 2 column composite key on a table and on one of the fields, I wanted to use an enumerated type which had a custom IUserType to translate it to its appropriate code value in the DB. Couldn't do it, so I was stuck keeping the property of the string type rather than the enumerated type.
I try to write a (fluent) mapping against an interface
public interface IOrderDiscount : IDomainObject<long>
where
public interface IDomainObject<IdT> : IDomainObject
{
IdT Id { get; }
}
like so (and all other thinkable varieties of access strategies)
Id(d => d.Id, "DiscountId")
.GeneratedBy.HiLo("9")
.WithUnsavedValue(0)
.Access.AsReadOnlyPropertyThroughCamelCaseField();
but all I get are variations of
Could not find field 'id' in class 'IOrderDiscount'
My base class implements this as
public virtual IdT Id { get; protected set; }
but event using a backing field does not change a thing.
So I am left to wonder, how I could get this to work...
Anyone with an idea?
Specify the custom column name via the Column method instead:
Id(d => d.Id)
.Column("DiscountId")
.GeneratedBy.HiLo("9")
.WithUnsavedValue(0)
.Access.AsReadOnlyPropertyThroughCamelCaseField();