The index of a list is no property. It is just a column to allow NH to
read it in the same order back as it has been stored.
Not every column is a property. Foreign keys aren't, list indexes are
also no properties.
With a list of composite-elements your Property would only look like
this:
public class Property
{
public virtual string Name { get; set; }
}
And the table would have this columns:
ProductId (foreign key to product)
SortOrder
Name
On 14 Aug., 14:44, "Jeffrey Zhao" <je...@live.com> wrote:
> For the last question, the reason I use "Set" is that "List" in NH mapping
> has an "index". I tried to use the Property.SortOrder as the index but met a
> lot of problems. So I try to use a "sorted set" (as the doc mentioned) as a
> workaround.
>
> Thanks for your reply, I'll have a try later. I used Linq to SQL before and
> now I'm going to use NH but it seems much more complicated than L2S.
>
> Blog:http://www.cnblogs.com/JeffreyZhao/
> Twitter:http://twitter.com/jeffz_cn
>
> --------------------------------------------------
> From: "Stefan Steinegger" <stefan.steineg...@bluewin.ch>
> Sent: Friday, August 14, 2009 7:55 PM
> To: "nhusers" <nhusers@googlegroups.com>
> Subject: [nhusers] Re: How can I JUST delete an entity using NHibernate
>
>
>
> > You mapped the ProductID in the Property:
>
> > <class name="Property">
> > ...
> > <property name="Name"/>
> > <property name="SortOrder"/>
> > <property name="ProductID" /> <<== evil
> > </class>
>
> > This probably resets the product id with the property value, which is
> > not initialized.
>
> > Consider to have a full reference to product (don't forget to make the
> > set inverse="true") or just leave it away.
>
> > You are working with an ORM. This means: you don't have any relational
> > stuff in your class model. So you shouldn't have "foreign keys" there.
>
> > BTW, you probably should map it like this:
>
> > <set name="Properties" cascade="all" table="Product_Details">
> > <key column="ProductID" on-delete="cascade"/>
> > <composite-element type="Property">
> > <property name="Name"/>
> > <property name="..."/>
> > </composite-element>
> > </set>
>
> > This makes it a list of value-type-alike instances. Property will not
> > have an id anymore.
> > Seehttp://nhforge.org/doc/nh/en/index.html#components
>
> > And - why is it a set if you need a sort order? It should probably be
> > a list.
>
> > On 14 Aug., 12:38, "Jeffrey Zhao" <je...@live.com> wrote:
> >> Thanks, I tried. As the post said, I changed the mapping sittings like:
>
> >> <set name="Properties" cascade="all(or save-update)" lazy="true"
> >> inverse="true">
> >> <key column="ProductID" on-delete="cascade" />
> >> <one-to-many class="Property"/>
> >> </set>
>
> >> And now NH just execute an DELETE sql as I want. But, I cannot correctly
> >> insert the data now:
>
> >> var product = new Product { Name = "Product" };
> >> product.Properties.Add(new Property { Name = "P0", SortOrder = 0 });
> >> product.Properties.Add(new Property { Name = "P1", SortOrder = 1 });
> >> session.Save(product);
> >> session.Flush();
>
> >> But now the data in database is:
>
> >> table Product
> >> ProductID Name
> >> ----------- --------------------------------------------------
> >> 9 Product
>
> >> table Property
> >> PropertyID ProductID Name
> >> SortOrder
> >> ----------- ----------- --------------------------------------------------
> >> -----------
> >> 12 0 P0
> >> 0
> >> 13 0 P1
> >> 1
>
> >> The ProductID column in Property should be 9 but 0.
>
> >> // PS: I cannot find the discription of on-delete attribute in the
> >> doc:http://nhforge.org/doc/nh/en/index.html.
>
> >> Blog:http://www.cnblogs.com/JeffreyZhao/
> >> Twitter:http://twitter.com/jeffz_cn
>
> >> --------------------------------------------------
> >> From: "Stefan Steinegger" <stefan.steineg...@bluewin.ch>
> >> Sent: Friday, August 14, 2009 5:59 PM
> >> To: "nhusers" <nhusers@googlegroups.com>
> >> Subject: [nhusers] Re: How can I JUST delete an entity using NHibernate
>
> >> > Try
>
> >> > Product product = session.Load<Product>(1);
> >> > session.Delete(product);
>
> >> > This should actually only create a proxy for the Product 8assuming you
> >> > are using lazy loading). Then you can remove it.
>
> >> > then you can use on-delete in the mapping to let the database clean up
> >> > referenced records:
> >> >http://vanryswyckjan.blogspot.com/2008/04/nhibernate-20-and-cascading...
>
> >> > On 14 Aug., 11:12, "Jeffrey Zhao" <je...@live.com> wrote:
> >> >> Hello,
>
> >> >> I'm a new for NH and I met the problem of "how can I delete an
> >> >> entity".
> >> >> For example, I've got two entity with an one-to-many association.
> >> >> Here's the sql to build the table (omit the association):
>
> >> >> CREATE TABLE [dbo].[Property](
> >> >> [PropertyID] [int] IDENTITY(1,1) NOT NULL,
> >> >> [ProductID] [int] NOT NULL,
> >> >> [Name] [nvarchar](50) NOT NULL,
> >> >> [SortOrder] [int] NOT NULL,
> >> >> CONSTRAINT [PK_Property] PRIMARY KEY CLUSTERED
> >> >> (
> >> >> [PropertyID] ASC
> >> >> ))
> >> >> GO
>
> >> >> CREATE TABLE [dbo].[Product](
> >> >> [ProductID] [int] IDENTITY(1,1) NOT NULL,
> >> >> [Name] [nvarchar](50) NOT NULL,
> >> >> CONSTRAINT [PK_Product] PRIMARY KEY CLUSTERED
> >> >> (
> >> >> [ProductID] ASC
> >> >> ))
> >> >> GO
>
> >> >> Here comes the entities:
>
> >> >> public class Product
> >> >> {
> >> >> public virtual int ProductID { get; set; }
> >> >> public virtual string Name { get; set; }
> >> >> public virtual ISet<Property> Properties { get; set; }}
>
> >> >> public class Property
> >> >> {
> >> >> public virtual int PropertyID { get; set; }
> >> >> public virtual int ProductID { get; set; }
> >> >> public virtual string Name { get; set; }
> >> >> public virtual int SortOrder { get; set; }
>
> >> >> }
>
> >> >> and my hbm.xml file:
>
> >> >> <?xml version="1.0" encoding="utf-8" ?>
> >> >> <hibernate-mapping xmlns="urn:nhibernate-mapping-2.2"
> >> >> assembly="NHTest"
> >> >> namespace="NHTest">
> >> >> <class name="Product" table="Product">
> >> >> <id name="ProductID" column="ProductID">
> >> >> <generator class="identity"/>
> >> >> </id>
> >> >> <property name="Name"/>
> >> >> <set name="Properties" cascade="all">
> >> >> <key column="ProductID"/>
> >> >> <one-to-many class="Property"/>
> >> >> </set>
> >> >> </class>
> >> >> <class name="Property">
> >> >> <id name="PropertyID">
> >> >> <generator class="identity"/>
> >> >> </id>
> >> >> <property name="Name"/>
> >> >> <property name="SortOrder"/>
> >> >> <property name="ProductID" />
> >> >> </class>
> >> >> </hibernate-mapping>
>
> >> >> well, that's quite simple, and I can insert one Product with two
> >> >> Properties without problem, but how can I delete the Product with ID
> >> >> equals 1? I tried:
>
> >> >> session.Delete(new Product { ProductID = 1 });
> >> >> session.Flush();
>
> >> >> But NH always want to update the properties' ProductID to NULL, but my
> >> >> schema won't accept the change (for NOT NULL). I tried every cascade
> >> >> settings in the <set /> element but always faild by updating.
> >> >> I just want to execute the SQL like "DELETE FROM Product WHERE
> >> >> ProductID
> >> >> = 1" and everything else could be done in database. (e.g., cascade
> >> >> deletion).
> >> >> What should I do?
>
> >> >> Blog:http://www.cnblogs.com/JeffreyZhao/
> >> >> Twitter:http://twitter.com/jeffz_cn
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