I am trying to save a new entity 'Post' with 1 item added to its 'Revisions' List.
A Post can have many PostRevisions, and a PostRevision can only have one Post.
I have tried several ways of mapping the PostRevisions, my PostRevisionMap is as follows:
public PostRevisionMap()
{
Id(x => x.PostRevisionId, "PostRevisionId");
Map(x => x.Created, "CreateDateTime").Not.Nullable();
/// SOME OTHER STUFF HERE
References(x => x.Post, "PostId"); // OPTION 1
References(x => x.Post,"PostId").ForeignKey("PostId").PropertyRef(d => d.PostId); // OPTION 2
HasOne<Post>(x => x.Post).ForeignKey("PostId").Cascade.All().PropertyRef(x => x.PostId); // OPTION 3
}
When calling SaveOrUpate I get a different errors
OPTION 1 & 3 cause
The INSERT statement conflicted with the FOREIGN KEY constraint "PostId".
OPTION 2 causes
NHibernate.HibernateException : Unable to resolve property: PostId
My PostMap is as follows:
public PostMap()
{
Id(x => x.PostId).Column("PostId");
HasMany(x => x.Revisions)
.Cascade.All()
.Table("PostRevisions")
.KeyColumn("PostId")
.ForeignKeyConstraintName("FK_PostRevision_Post");
/// OTHER STUFF
}
Can anyone point me in the right direction as I can not spot the issue.
TIA
Try this:
PostMap
HasMany(x => x.Revisions)
.Inverse()
.Cascade.All();
PostRevisionMap:
References(x => x.Post);
Related
I have a problem where I have a many-to-many mappings in my table structure creating headaches when trying to edit a simple record.
Example layout of where I am having problems:
Facilities Many-to-One Locations
Facilities One-to-Many Users
Users Many-to-Many Locations
Users One-to-Many PreviousPasswords
If I make a change to a Facilities record (Change the name field) I get the following error upon save:
collection [Users.PreviousPasswords] was not processed by flush()
Mapping looks like:
public FacilitiesMap()
{
Table("Facilities");
Id(x => x.ID);
Map(x => x.Name);
HasMany(x => x.Users).KeyColumn("FacilitiesID").Cascade.AllDeleteOrphan().Inverse();
HasMany(x => x.Locations).KeyColumn("FacilitiesID").Cascade.AllDeleteOrphan().Inverse();
}
public UsersMap()
{
Table("Users");
Id(x => x.ID);
Map(x => x.FirstName);
Map(x => x.LastName);
References(x => x.Facilities, "FacilitiesID").ForeignKey("ID");
HasMany(x => x.PreviousPasswords).KeyColumn("UsersID").Cascade.AllDeleteOrphan().Inverse();
HasManyToMany<Locations>(x => x.Locations)
.Schema("Members")
.Table("UsersToLocations")
.ParentKeyColumn("UsersID")
.ChildKeyColumn("LocationsID")
.LazyLoad()
.Cascade.SaveUpdate().Inverse();
}
public LocationsMap()
{
Table("Locations");
Id(x => x.ID);
Map(x => x.Name);
References(x => x.Facilities, "FacilitiesID").ForeignKey("ID");
HasMany(x => x.Patients).KeyColumn("LocationsID").Cascade.AllDeleteOrphan().Inverse();
HasManyToMany<Users>(x => x.Users)
.Schema("Members")
.Table("UsersToLocations")
.ParentKeyColumn("LocationsID")
.ChildKeyColumn("UsersID")
.Cascade.SaveUpdate();
}
public PreviousPasswordsMap()
{
Table("PreviousPasswords");
Id(x => x.ID);
Map(x => x.Password);
Map(x => x.DateTime);
References(x => x.Users, "UsersID").ForeignKey("ID");
}
The only way I can do a successful update to the Facilities record is if I use the following function to get the record before changing and saving it:
public Facilities GetFacility(int id)
{
return FluentSessionManager.GetSession()
.CreateCriteria<Facilities>()
.Add(Expression.Eq("ID", id))
.SetFetchMode("Users", FetchMode.Eager)
.SetFetchMode("Locations", FetchMode.Eager)
.UniqueResult<Facilities>();
}
The problem with this method is that where there are 10,000 users it takes a long time to process this query. Or even worse, if we have 100 location as well, then it takes around 2 minutes to get the one Facilities record to edit.
I am sure there is some kind of issue in the Mapping. Not sure how to fix or even where to start. Any help with this would be greatly appreciated.
Thanks in advance.
Do you really need all the users for the facility? When you only add users you can use
HasMany(x => x.Users).ExtraLazyLoad();
and to improve the query when really all subcollections are needed
public Facilities GetFacility(int id)
{
var session = FluentSessionManager.GetSession();
// ignore the result, we only want to cache the results in the session
session.CreateCriteria<Facilities>()
.Add(Expression.Eq("ID", id))
.SetFetchMode("Users", FetchMode.Eager)
.Future<Facilities>();
return session.CreateCriteria<Facilities>()
.Add(Expression.Eq("ID", id))
.SetFetchMode("Locations", FetchMode.Eager)
.FutureValue<Facilities>().Value;
}
I am using fluent nhibernate(v1.2) and nhibernate(v3.1) and I am having a weird Problem.
I have this
public class GradeMap : ClassMap<Grade>
{
public GradeMap()
{
Id(x => x.GradeId);
Map(x => x.TaskName).NvarcharWithMaxSize().Not.Nullable();
Map(x => x.Weight).Not.Nullable().Precision(5).Scale(2);
Map(x => x.OutOf).Not.Nullable().Precision(5).Scale(2);
Map(x => x.Mark).Not.Nullable().Precision(5).Scale(2);
Map(x => x.CourseBackgroundColor).Not.Nullable();
Map(x => x.CoursePrefix).Not.Nullable();
References(x => x.Student).Not.Nullable();
References(x => x.Course);
}
}
public class CourseMap : ClassMap<Course>
{
public CourseMap()
{
Id(x => x.Id).Column("CourseId");
Map(x => x.Prefix).NvarcharWithMaxSize().Not.Nullable();
HasMany(x => x.Tasks).Cascade.Delete().Inverse();
HasMany(x => x.CoursePermissions).Cascade.All().Inverse();
HasMany(x => x.CourseSharing).Cascade.All().Inverse();
HasMany(x => x.Grades).Cascade.None().Inverse();
}
}
I then do something like this
return session.Query<Grade>().ToList();
If I would try to grab a propety such as Grade.Course.Id it would crash and I would get.
Grade.Course = {Castle.Proxies.CourseProxy}
Grade.Course.Id = '((new System.Collections.Generic.Mscorlib_CollectionDebugView<OnlGrade>(grades)).Items[0].Course).Id' threw an exception of type 'NHibernate.ObjectNotFoundException'
Grade.Course.Prefix = above error except .Prefix instead of .Id
I would have thought Course Object would be empty or null. Not that it would have some Proxy with all properties throwing exceptions.
Edit
I found this posting but I don't have this attribute anymore so maybe they got rid of it or moved it.
Anyone know?
Is it possible to avoid NHibernate.ObjectNotFoundException when there is a foreign key but the referenced row does not exist?
I think the error here is because you're accessing the Id property of an object which does not exist.
Do you get the same error if you do TableA.TableB ?
What about NotFound.Ignore()?
public class GradeMap : ClassMap<Grade>
{
public GradeMap()
{
Id(x => x.GradeId);
Map(x => x.TaskName).NvarcharWithMaxSize().Not.Nullable();
Map(x => x.Weight).Not.Nullable().Precision(5).Scale(2);
Map(x => x.OutOf).Not.Nullable().Precision(5).Scale(2);
Map(x => x.Mark).Not.Nullable().Precision(5).Scale(2);
Map(x => x.CourseBackgroundColor).Not.Nullable();
Map(x => x.CoursePrefix).Not.Nullable();
References(x => x.Student).Not.Nullable();
References(x => x.Course)
.NotFound.Ignore();
}
}
EDIT:
Let's say database schema looks like this:
Grade(GradeId, TaskName, Course_id)
Course(CourseId, Prefix)
If there is no foreign key constraint on Course_id column, then row in Course table with CourseId that corresponds to Course_id column in Grade table can be deleted. E.g.:
Course table:
CourseId Prefix
1 Course1Prefix
Grade table:
GradeId TaskName Course_id
1 Grade1Task 1
without foreign key constraint you can issue this dml query:
delete from Course where CourseId = 1
And it could be reason of problem explained by sJhonny.
When "NotFound.Ignore()" is used in the mapping then NHibernate tries to load Courses that belong to all Grades that were loaded by the query:
session.Query<Grade>().ToList();
No proxies are generated and when course referenced by grade is not found in database then the Course property is simply null.
If you can modify the database schema it would be helpful to create PK constraint on Course_id column.
I have the following Fluent Mappings:
public ScanDeliverySessionMap()
{
Id(x => x.Id);
...
...
HasManyToMany(x => x.ToScanForms) <--- IList<Form> ToScanForms --->
.Table("ToScanForm")
.ParentKeyColumn("SessionId")
.ChildKeyColumn("FormId").Cascade.SaveUpdate();
}
public FormMap()
{
Id(x => x.Id).Column("FormID").GeneratedBy.Foreign("Log");
....
....
HasManyToMany(x => x.ScanDeliverySessions)
.Table("ToScanForm")
.ParentKeyColumn("FormId")
.ChildKeyColumn("SessionId").Inverse();
}
When I try to insert new Form to the ToScanForms collection
Everything seemingly works properly but watching on NHProf
I see that NH casacde DELETE over all ToScanForms items
and then NH INSERT the ToScanForms items including the new item.
Some screenshots:
That behaviour occurs because nhibernate doesn't know which entities in the collection are new and which are old, so he must delete everything and then re-insert them.
To prevent this is behaviour is quite simple: change your property to an ICollection and map your HasManyToMany as a set. You mapping would be changed to the following:
public ScanDeliverySessionMap()
{
Id(x => x.Id);
...
...
HasManyToMany(x => x.ToScanForms) //<--- ICollection<Form> ToScanForms --->
.AsSet()
.Table("ToScanForm")
.ParentKeyColumn("SessionId")
.ChildKeyColumn("FormId").Cascade.SaveUpdate();
}
public FormMap()
{
Id(x => x.Id).Column("FormID").GeneratedBy.Foreign("Log");
....
....
HasManyToMany(x => x.ScanDeliverySessions)
.AsSet()
.Table("ToScanForm")
.ParentKeyColumn("FormId")
.ChildKeyColumn("SessionId").Inverse();
}
Under the hood nhibernate will use Iesi Collections' HashSet, so now he knows which entities are new and which are old.
having a little trouble with a mapping for the following table setup currently:
Shop
[1] [1]
/ \
[n] [n]
Category-[m]---[n]-Article
The behaviour should be the following :
1 - when deleting a shop, all Articles and Categories Should be deleted
2 - when deleting a Category, related Articles should be unassigned but not deleted
3 - when deleting an Article, related Categories should be unassigned but not deleted
Here's the current mapping:
public class ShopMap: ClassMap<Shop>
{
public ShopMap()
{
this.Table("shop");
Id(x => x.Id).Column("id").GeneratedBy.Native();
Map(x => x.Name).Column("name");
HasMany(x => x.Categories).Cascade.AllDeleteOrphan;
HasMany(x => x.Articles).Cascade.AllDeleteOrphan;
}
}
public class CategoryMap: ClassMap<Category>
{
public CategoryMap()
{
this.Table("category");
Id(x => x.Id).Column("id").GeneratedBy.Native();
Map(x => x.Name).Column("name");
References(x => x.Shop);
HasManyToMany(x => x.Articles).Cascade.AllDeleteOrphan()
.Table("article_category")
.ChildKeyColumn("article_id")
.ParentKeyColumn("category_id")
.Inverse();
}
}
public class ArticleMap: ClassMap<Article>
{
public ArticleMap()
{
this.Table("article");
Id(x => x.Id).Column("id").GeneratedBy.Native();
Map(x => x.Name).Column("name");
References(x => x.Shop);
HasManyToMany(x => x.Categories).Cascade.All()
.Table("article_category")
.ParentKeyColumn("article_id")
.ChildKeyColumn("category_id");
}
}
When deleting a Category (Session.Delete()), NH tries to delete the related Articles as well. Changing the Cascade-Mode to SaveUpdate will fix this, but will leave the entries in the link table *article_category*. Summing up : Cascade.SaveUpdate is too lazy, Cascade.All is too eager.
I tried everything that came to my mind in the mappings, but couldn't find a correct way to map this (rather simple schema).
Any ideas on how to (fluently) map this are greatly appreciated!
Thanks in advance
Sebi
The entries are left in the link table because Category.Articles is defined as the inverse side of the relationship. You need to remove the Category from Article.Categories before deleting it in order for the link record to be removed.
I am having a problem in Fluent NHibernate example utilizing the Many-to-Many relationships. I tried to find out examples on a similar case, and I found tons, but I'm still having the same problem.
When running the test project, the following exception is thrown:
NHibernate.PropertyAccessException: Exception occurred getter of project.Entities.User.UserName ---> System.Reflection.TargetException: Object does not
match target type.
This is an image of the tables:
and the code
public UsersMap()
{
this.Table("Users");
Id(x => x.UserName).Column("Username").GeneratedBy.Assigned();
Map(x => x.FirstName);
Map(x => x.LastName);
Map(x => x.Password);
Map(x =>x.EMail);
Map(x => x.Title);
Map(x => x.Division);
HasManyToMany<User>(x => x.Roles)
.Table("UserInRoles").ParentKeyColumn("Username")
.ChildKeyColumn("Usernamepk")
.Cascade.SaveUpdate().LazyLoad();
}
public RolesMap()
{
this.Table("Roles");
Id(x => x.ID).GeneratedBy.Assigned().Column("ID");
Map(x => x.RoleName).Length(50);
HasManyToMany<User>(x => x.Users)
.Table("UserInRoles").ParentKeyColumn("ID")
.ChildKeyColumn("RoleIdpk").Cascade.SaveUpdate().LazyLoad();
}
here is the code, most examples on the web and the Fluent Nhibernate mappings page are written in the same way, so any ideas ?
Regarding to code I am using in my project I would define your manyTomany relations this way:
public UsersMap()
{
...
HasManyToMany(x => x.Roles)
.WithTableName("UserInRoles")
.WithParentKeyColumn("Usernamepk")
.WithChildKeyColumn("RoleIdpk");
}
public RolesMap()
{
...
HasManyToMany(x => x.Users)
.WithTableName("UserInRoles")
.WithParentKeyColumn("RoleIdpk")
.WithChildKeyColumn("Usernamepk");
}
Such a definitions works for me.
Check this first then decorate with LazyLoading and some other properties.