how to do a classmapping (nh3.2) and a many_to_many set

[ike]

Hi,

I'm looking at the new classmapping stuff that got added in the 3.2
release of nh.

To test this out, I'm converting the hbm-mappings of the alexandria
project to classmappings.
However, I'm running into a problem when mapping a set or a list.
Exception: unknown column "elt".
Clearly there's something wrong in the my mappings, but I just can't
seem to figure it out.

Alexandria:
https://github.com/ayende/Alexandria

I will paste a portion of the hbm (which works)
<set name="CurrentlyReading" table="UsersReadingBooks">
<key column="`User`"/>
<many-to-many class="Book" column="Book"/>
</set>

portion of my mapping (which doesn't work)
Set(x => x.CurrentlyReading, mapper =>
{

mapper.Table("UsersReadingBooks");
mapper.Key(y =>
y.Column("`User`"));
}, element =>
{
element.ManyToMany(y
=>
{

y.Class(typeof (Book));

y.Column("Book");

y.ForeignKey("Book");
});
element.Element(y =>
y.Column("Book"));
});
My guess was that y.Column in the manytomany would be sufficient, but
it's not. That's why I tried all the things that looked like it could
be that too. But it still doesn't work.

Can someone see what's wrong with my mapping?

Thanks,
Ike

[letspirate]

hi guys

does anyone know how to create many-to-may relationship in mapping by
code in NHibernate 3.2?

thanks in advance

[Fabio Maulo]

Where you wrote:

element.Element(y => y.Column("Book")); 

which are the others methods of "element" ?

[ike]

Hi Fabio,

I think you want me to find the solution by guiding me to it (which is
cool), but I still don't see it (or I didn't understand your remark).

element has following methods
-> Component (if I use this, complains that "Book" is mapped as an
entity and a component (ambigues mapping))
-> Element -> using this one
-> ManyToAny (and a generic one) -> it's manytomany
-> ManyToMany -> using this one
-> OneToMany -> it's manytomany

Best regards,
Ike

[José F. Romaniello]

ike, for me it seems that with your fluent code you  are trying to map a "Dictionary" instead of a plain collection... something like this should work:

           mapper.Class<YourClass>(map => map.Set(p => p.CurrentlyReading,
                                         set => set.Cascade(Cascade.All),
                                         rel => rel.ManyToMany()));

[ike]

Hi José,

I'm using classmapping
public class UserMapping : ClassMapping<User>

but the "Set" method looks the same as doing it directly via the
mapper.Class method.

The difference I see, is the cascade that got added and the rest that
is ommited.
I have tried the code above, but I get the same results.

I have added below my entire code (entities, mapping and a bit of
dbinfo), that might help pinpoint my problem.

Thanks,
Ike


Here's the full code of the entities
public class User
{
public virtual long Id { get; set; }

public virtual string Name { get; set; }
public virtual Address Address { get; set; }

public virtual IList<Book> Recommendations { get; set; }
public virtual IList<Book> Queue { get; set; }
public virtual ICollection<Book> CurrentlyReading { get; set; }
public virtual ICollection<Subscription> Subscriptions { get; set; }
}
public class Book
{
public virtual long Id { get; set; }
public virtual string Name { get; set; }
public virtual string ImageUrl { get; set; }
public virtual byte[] Image { get; set; }
public virtual string Author { get; set; }
}
public class Address
{
public virtual string Street { get; set; }
public virtual string Country { get; set; }
public virtual string City { get; set; }
public virtual string ZipCode { get; set; }
public virtual string HouseNumber { get; set; }
}
public class Subscription
{
public virtual long Id { get; set; }
public virtual int NumberOfPossibleBooksOut { get; set; }
public virtual decimal MonthlyCost { get; set; }
public virtual string CreditCard { get; set; }
public virtual User User { get; set; }
public virtual DateTime Start{ get; set; }
public virtual DateTime End { get; set; }
}


Here's my mapping code
public class UserMapping : ClassMapping<User>
{
public UserMapping()
{
Table("Users");

Id(x => x.Id, mapper =>
mapper.Generator(Generators.HighLow));

Property(x => x.Name, mapper =>
mapper.NotNullable(false));

Component(x => x.Address, mapper =>
{
mapper.Property(y =>
y.Street);
mapper.Property(y =>
y.Country);
mapper.Property(y =>
y.City);
mapper.Property(y =>
y.ZipCode);
mapper.Property(y =>
y.HouseNumber);
});

List(x => x.Queue, mapper =>
{
mapper.Table("UsersWaitingBooks");

mapper.Key(y =>
y.Column("`User`"));

mapper.Index(y =>
y.Column("`Index`"));

}, element =>
{
element.ManyToMany(y =>
{

y.Class(typeof (Book));

y.Column("Book");

});

element.Element(y =>
y.Column("Book"));

});

List(x => x.Recommendations, mapper =>
{

mapper.Table("UsersRecommendedBooks");

mapper.Key(y =>
y.Column("`User`"));

mapper.Index(y =>
y.Column("`Index`"));
}, element =>
{

element.ManyToMany();

element.Element(y
=> y.Column("Book"));

});

Set(x => x.CurrentlyReading, mapper =>
{

mapper.Cascade(Cascade.All);

mapper.Table("UsersReadingBooks");
mapper.Key(y =>
y.Column("`User`"));
}, element =>
{

element.Element(er =>
er.Column("Book"));
element.ManyToMany(z
=> z.ForeignKey("Book"));
});
Set(x => x.Subscriptions, mapper => mapper.Key(y =>
y.Column("`User`")), element => element.OneToMany());
}
}

public class SubscriptionMapping : ClassMapping<Subscription>
{
public SubscriptionMapping()
{
Table("Subscriptions");

Id(x => x.Id, mapper =>
mapper.Generator(Generators.HighLow));

Property(x => x.NumberOfPossibleBooksOut, mapper =>
mapper.NotNullable(false));
Property(x => x.CreditCard, mapper =>
mapper.NotNullable(false));
Property(x => x.MonthlyCost, mapper =>
mapper.NotNullable(false));
Property(x => x.Start, mapper =>
mapper.NotNullable(false));
Property(x => x.End, mapper =>
{
mapper.NotNullable(false);
mapper.Column("`End`");
});
ManyToOne(x => x.User, mapper =>
{
mapper.Column("`User`");
mapper.NotNullable(true);
});
}
}

public class BookMapping : ClassMapping<Book>
{
public BookMapping()
{
Table("Books");

Id(x => x.Id, mapper =>
mapper.Generator(Generators.HighLow));

Property(x => x.Name, mapper =>
mapper.NotNullable(false));
Property(x => x.ImageUrl, mapper =>
mapper.NotNullable(false));
Property(x => x.Image, mapper =>
{
mapper.NotNullable(false);
mapper.Length(131072);
});
Property(x => x.Author, mapper =>
mapper.NotNullable(false));
}
}

The database has UserS, BookS, UsersReadingBooks tables.
The UsersReadingBooks has 2 columns (Book, User)

[ike]

Hi,

I think there might be a bug here.
It has to do with the "casing"

The mapping.

Set(x => x.CurrentlyReading, mapper =>
{

mapper.Table("UsersReadingBooks");
mapper.Key(y => y.Column("`User`"));
}, element =>
{

element.ManyToMany(y =>
{
y.Class(typeof(Book));
y.Column("Book");
//y.Column("book");
});
});

Generated sql:
SELECT currentlyr0_.[User] as User1_1_, currentlyr0_.elt as elt1_,
book1_.Id as Id4_0_, book1_.Name as Name4_0_, book1_.ImageUrl as
ImageUrl4_0_, book1_.Image as Image4_0_, book1_.Author as Author4_0_
FROM UsersReadingBooks currentlyr0_ left outer join Books book1_ on
currentlyr0_.elt=book1_.Id WHERE currentlyr0_.[User]=?

The problem is the "currentlyr0_.elt"-column that doesn't exists. This
should be "currentlyr0_.Book".

However is I use y.Column("book") -> all in lowercase, then the
generated sql is as it should be

Best regards,
Ike