I have a table called openTickets. I have another table called openTicketFollowers that relates to it using a foreign key. OpenTickets does not know about openTicketFollowers but I want openTickets to have a property that is a list of its followers. Is there anyway to do this with fluent nhibernate?
Check this Fluent mapping document. The OpenTicket class will contain IList of Followers:
public class OpenTicket
{
...
public virtual IList<OpenTicketFollower> Followers { get; set; }
}
public class OpenTicketFollowers
{
public virtual OpenTicket OpenTicket { get; set; }
}
And this is fluent mapping of the OpenTicketFollowercollection:
HasMany(x => x.Followers)
.KeyColumn("OpenTicketId");
and the OpenTicketFollower class mapping referencing the OpenTicket
References(x => x.OpenTicket)
.Column("OpenTicketId")
Related
I want to combine table-per-class and table-per-hierarchy strategies using fluent nhibernate or nhibernate itself(I mean hbm files), but I don't know how. I prefer fluent over hbm but if it's impossible, then hbm is also fine. I tested this by introducing Entity as ClassMap and all other as SubClassMap in fluent but then in hbm files generated by fluent, Entity was a class and all other were joined-classes which is not what I want. I will describe the problem in more detail below.
Class hierarchy:
public class Entity
{
public int ID { get; set; }
public string Name { get; set; }
}
public abstract class Person : Entity
{
public string Phone { get; set; }
}
public class SystemUser : Person
{
public string Password { get; set; }
}
I want to have one table for entity and one for person and all kinds of it(all its subclasses).I mean I want to use table-per-class strategy for Entity and table-per-hierarchy strategy for Person and SystemUser classes. Database structure is something like this:
EntityTable(ID(PK),Name)
PersonTable(EntityID(PK,FK),Phone,Password)
any help appreciated.
if EntityTable Id is not database generated (which is discouraged by NH anyways) you can use the trick
public PersonMap : ClassMap<Person>
{
public PersonMap()
{
Table("PersonTable");
Id(p => p.Id, "EntityID").GeneratedBy.HiLo("100");
DiscriminateSubClassesOnColumn("PersonType");
Map(x => x.Phone);
Join("EntityTable", join =>
{
join.KeyColumn("ID");
join.Map(p => p.Name);
});
}
}
public SystemUserMap : SubclassMap<SystemUser>
{
public SystemUserMap()
{
Map(x => x.Password);
}
}
After reading some of the articles about Fluent NHibernate I got confused from where to start
I have an existing database to which I need to create DataAccessLayer. I am new to NHibernate and FluentNhibernate. Since I understood that there is no need to write hbm.xml files, I picked Fluent Nhibernate.
So, What is FluentMapping? and AutoMapping?
I have created a classLibraryProject named FirstProject.Entities
I have created a class named "Customer"
namespace FirstProject.Entities
{
public class Customer
{
public virtual int CustomerID { get; set; }
public virtual string CustomerName { get; set; }
public virtual string Address1 { get; set; }
public virtual string Address2 { get; set; }
public virtual string City { get; set; }
public virtual string State { get; set; }
public virtual int Zip { get; set; }
}
}
Then I created a Mapping class
namespace FirstProject.Entities
{
public class CusotmerMap : ClassMap<Customer>
{
public CustomerMap()
{
Id(x => x.CustomerID).Column("CustomerID").GeneratedBy.Assigned();
Map(x => x.CustomerName);
Map(x => x.Address1);
Map(x => x.Address2);
Map(x => x.City);
Map(x => x.Zip);
}
}
}
I now don't know how to proceed further. Am I doing it right.. please suggest
how to configure and proceed further
The following is Fluent
Id(x => x.CustomerID).Column("CustomerID").GeneratedBy.Assigned();
I use Fluent assertions, like the following
actual.Should().BeGreaterThan(1).And().LessThan(2);
Fluent is basically where you chain together the commands such that it reads quite well.
Auto mapping is where you do nothing. Everything is done by conventions. I tend to use Auto. Fluent is nice if you don't follow conventions.
Based on your mapping, the CustomerId being Assigned is not the out-of-the-box convention. As such you need to either
Use Fluent to specify exactly how it should map. This is just like doing it the standard way in XML, but with a fluent interface.
Use Auto and specify a Convention that will automatically change CustomerId to be Assigned.
Use Auto and specify an Override, that will use Auto but override CustomerId to be Assigned.
If you want to do option 3, here is the code:
var model = AutoMap
.AssemblyOf<Customer>()
.Where(IsMapped)
.Override<Customer>(a => a.Id(b => b.CustomerId, "CustomerId").GeneratedBy.Assigned());
The function IsMapped must return True for entities you want to Map.
I am getting NHibernate.MappingException while trying to do one-to-many mapping in fluent nhibernate.
Below are the snippets from my entity and their mapping classes:
public class ReportRequest : IReportRequestToBeFullyLoaded
{
public virtual Int32? Id { get; set; }
public virtual string Description { get; set; }
public virtual ISet<ReportOutputEmail> ReportOutputEmails { get; set; }
}
public class ReportOutputEmail
{
public virtual string RecipientAddress { get; set; }
public virtual string Message { get; set; }
public virtual ReportRequest ReportRequest { get; set; }
}
public class ReportRequestMap : ClassMap<ReportRequest>
{
public ReportRequestMap()
{
Table("ReportRequest");
Id(x => x.Id).UnsavedValue(null).GeneratedBy.Native();
Map(x => x.Description);
HasMany(x => x.ReportOutputEmails).Table("ReportOutputEmail")
.ForeignKeyConstraintName("FK_ReportOutputEmail_ReportRequest")
.KeyColumn("ReportRequestId")
.AsSet()
.Inverse()
.Cascade.AllDeleteOrphan();
}
}
public class ReportOutputEmailMap: ClassMap<ReportOutputEmail>
{
public ReportOutputEmailMap()
{
References(x => x.ReportRequest)
.ForeignKey("FK_ReportOutputEmail_ReportRequest")
.Column("ReportRequestId");
Map(x => x.RecipientAddress);
Map(x => x.Message);
}
}
There is some issue with one-to-many mapping between ReportRequest->ReportOutputEmail,
Getting error:
Error: NHibernate.MappingException: (XmlDocument)(3,6): XML validation error: The
element 'class' in namespace 'urn:nhibernate-mapping-2.2' has invalid child element
'property' in namespace 'urn:nhibernate-mapping-2.2'. List of possible elements expected: 'meta, subselect, cache, synchronize, comment, tuplizer, id, composite-id' in namespace 'urn:nhibernate-mapping-2.2'.
Can anyone help figuring out.
Thank you!
Your ReportOutputEmail doesn't have an identity, it'll need one if its going to be an entity.
Also, I recommend you upgrade your copy of Fluent NHibernate, as this is reported in a much more helpful manner since 1.1 (you'd get an identity missing message).
What is the best way of mapping a simple Dictionary property using Fluent NHibernate?
public class PersistedData
{
public virtual IDictionary<key, value> Dictionary { get; set; }
}
public class PersistedDataMap : ClassMap<PersistedData>
{
HasMany(x => x.Dictionary)
.Table("dict_table")
.KeyColumn("column_id")
.AsMap<string>("key")
.Element("value");
}
This will properly map Dictionary to table dict_table and use column_id to associate it to the base id.
As a side note, if you would like to use an Enum as the Key in the dictionary, it should be noted that NHibernate.Type.EnumStringType<MyEnum> can be used in place of the string in .AsMap<string> to use the string value instead of the Ordinal.
Using a simple class relationship such as the following:
public class Foo {
public virtual IDictionary<string, Bar> Bars { get; set; }
}
public class Bar {
public virtual string Type { get; set; }
public virtual int Value { get; set; }
}
You can map this with Fluent NHibernate in this way:
mapping.HasMany(x => x.Bars)
.AsMap(x => x.Type);
Where Bar.Type is used as the key field into the dictionary.
To map a list as a dictionary:
HasMany(x => x.Customers)
.AsMap();
I have not used it; so cannot give an example.
Have look at the wiki: Cached version of the page, Actual page I have given the cached version of the page as the site seems to be down.
Basic question: How to I create a bidirectional one-to-many map in Fluent NHibernate?
Details:
I have a parent object with many children. In my case, it is meaningless for the child to not have a parent, so in the database, I would like the foreign key to the parent to have NOT NULL constraint. I am auto-generating my database from the Fluent NHibernate mapping.
I have a parent with many child objects like so:
public class Summary
{
public int id {get; protected set;}
public IList<Detail> Details {get; protected set;}
}
public class Detail
{
public int id {get; protected set;}
public string ItemName {get; set;}
/* public Summary Owner {get; protected set;} */ //I think this might be needed for bidirectional mapping?
}
Here is the mapping I started with:
public class SummaryMap : ClassMap<Summary>
{
public SummaryMap()
{
Id(x => x.ID);
HasMany<Detail>(x => x.Details);
}
}
public class DetailMap : ClassMap<Detail>
{
public DetailMap()
{
Id(x => x.ID);
Map(x => x.ItemName).CanNotBeNull();
}
}
In the Detail table, the Summary_id should be Not Null, because in my
case it is meaningless to have a Detail object not attached to the
summary object. However, just using the HasMany() map leaves the Summary_id foreign key nullable.
I found in the NHibernate docs (http://www.hibernate.org/hib_docs/nhibernate/html/collections.html) that "If the parent is required, use a bidirectional one-to-many association".
So how do I create the bidirectional one-to-many map in Fluent NHibernate?
To get a bidirectional association with a not-null foreign key column in the Details table you can add the suggested Owner property, a References(...).CanNotBeNull() mapping in the DetailsMap class, and make the Summary end inverse.
To avoid having two different foreign key columns for the two association directions, you can either specify the column names manually or name the properties in a way that gives the same column name for both directions. In this case you I suggest renaming the Details.Owner property to Details.Summary.
I made the Summary id generated by increment to avoid problems when inserting into the table since Summary currenty has no columns besides id.
Domain:
public class Detail
{
public int id { get; protected set; }
public string ItemName { get; set; }
// Renamed to use same column name as specified in the mapping of Summary.Details
public Summary Summary {get; set;}
}
public class Summary
{
public Summary()
{
Details = new List<Detail>();
}
public int id { get; protected set; }
public IList<Detail> Details { get; protected set; }
}
Mapping:
public class DetailMap : ClassMap<Detail>
{
public DetailMap()
{
Id(x => x.id)
.GeneratedBy.Native();
Map(x => x.ItemName)
.CanNotBeNull();
References<Summary>(x => x.Summary)
// If you don't want to rename the property in Summary,
// you can do this instead:
// .TheColumnNameIs("Summary_id")
.CanNotBeNull();
}
}
public class SummaryMap : ClassMap<Summary>
{
public SummaryMap()
{
Id(x => x.id)
.GeneratedBy.Increment();
HasMany<Detail>(x => x.Details)
.IsInverse()
.AsBag(); // Use bag instead of list to avoid index updating issues
}
}