Unique key column order in fluent nhibernate - nhibernate

I try to create unique index with fluent nhibernate. But when i use the following classes
tables are created like :
Person Table:
Id
Name
PersonStatistic Table:
Id
Date
Count
Person_Id
Because of this structure when i create the unique key, column order look like "Date - Person_Id". But i want to column order in key like "Person_Id - Date"
Entity and map classes like below.
Entity classes :
public class Person()
{
public virtual Guid Id { get; set; }
public virtual string Name { get; set; }
}
public class PersonStatistic()
{
public virtual Guid Id { get; set; }
public virtual DateTime Date { get; set; }
public virtual long? Count { get; set; }
public virtual Person Person { get; set; }
}
Map classes :
public PersonMap()
{
Id(x => x.Id).GeneratedBy.GuidComb();
Map(x => x.Name).Not.Nullable().Length(50);
}
public PersonStatisticMap()
{
Id(x => x.Id).GeneratedBy.GuidComb();
Map(x => x.Date).Not.Nullable().UniqueKey("UK_Person_Date");
Map(x => x.Count).Nullable();
References(x => x.Person)
.Not.Nullable()
.UniqueKey("UK_Person_Date");
}
Something is wrong in my classes or mapping or another trick to set column order in key?

Try putting the References call before the Map one.

Related

Using References (many-to-one) in Fluent NHibernate creates a Foreign Key in both ends, the many end and the one-end

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!

Simple mapping in fluent nhibernate

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");

FluentNhibernate HasManytoMany Relation - It doesnt add into the link table

Using fluentnhibernate i am having a problem with the link table insertion.
Here is my entities
public partial class Item
{
public virtual int Id
{
get;
set;
}
public virtual string Description
{
get;
set;
}
public virtual IList<Category> Categories
{
get;
set;
}
}
public partial class Category
{
public virtual int Id
{
get;
set;
}
public virtual string Name
{
get;
set;
}
public virtual string Description
{
get;
set;
}
public virtual IList<Item> Items
{
get;
set;
}
}
Here is my mappings.
public class ItemMapping : ClassMap<Item>
{
public ItemMapping()
{
Table("Item");
Schema("dbo");
Id(x => x.Id);
Map(x => x.Description);
HasManyToMany(x => x.Categories)
.ChildKeyColumn("Item_id")
.ParentKeyColumn("Category_id")
.Table("CategoriesToItems")
.AsSet();
}
}
public class CategoryMapping : ClassMap<Category>
{
public CategoryMapping()
{
Table("Category");
Schema("dbo");
Id(x => x.Id);
Map(x => x.Description);
Map(x => x.Name);
HasManyToMany(x => x.Items)
.ChildKeyColumn("Category_id")
.ParentKeyColumn("Item_id")
.Table("CategoriesToItems")
.AsSet();
}
}
Here is how i add it to collection in my mvc page
var category = CategoryTask.Query(x => x.Id == post.Category).FirstOrDefault();
var item = new Item
{
Categories = new List<Category> { category },
Tags = tags
};
ItemTasks.Save(item);
My question is why it doesnt add the relations in my link table "CategoriesToItems". The table is already in the database with Category_Id (FK, int, not null) and Item_Id (FK, int, not null).
Where is the problem? why it doesnt add it to relation table?
It's hard to say what's really wrong when we can't see what your ItemTasks.Save does under the covers. Are you wrapping your save in a transaction? If not, you should be.
You should call Session.Flush() just before the transaction.Commit() as well.
I am not certain if the problem has been solved, but it looks similar to my problem (fluentnhibernate hasmanytomany same identifier exception).
Also, it looks like your parent and child key columns are backward.

Composite Key/Id Mapping with NHibernate

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

How do I create this reference mapping in Fluent NHibernate?

Using Fluent NHibernate I need a clue how to map my Invoice class.
public class Buyer
{
public virtual int Id { get; set; }
public virtual string Name { get; set; }
public virtual string TaxRegNo { get; set; }
// .... more properties....
}
public class Invoice
{
public virtual int Id { get; set; }
public virtual int IdBuyer { get; set; }
public virtual Buyer Buyer { get; set; }
// ....more properties
}
The problem is that I want to have in Invoice class:
BuyerId - just an integer ID for reference and foregin key relationship
a copy of almost all buyer properties (its accounting document and properties cannot be changed after confirmation) - as component
I tried to this using following mapping but it doesn't work
public InvoiceMap()
{
Id(x => x.Id);
References(x => x.IdBuyer);
Component(x => x.Buyer, BuyerMap.WithColumnPrefix("buyer_"));
// ....more properties
}
You would normally not map both the foreign key and the child object. If you do map both, then do this in the mapping (or similar):
References(x => x.Buyer);
Map(x => x.IdBuyer).Column("BuyerId").Not.Insert().Not.Update();
Then you don't double up on the column name in SQL statements, which causes errors around mismatched numbers of parameters.