Question

OK, I’m scratching my head once again. I have a class like so:

public class ReconciliationReportLineItem
{
    public virtual int ID { get; set; }
    public virtual int Category { get; set; }
    public virtual string FileName { get; set; }
    public virtual decimal Amount { get; set; }
    public virtual string BatchType { get; set; }
    public virtual DateTime CreatedTimeStamp { get; set; }
    public virtual string Currency { get; set; }
    public virtual decimal LocalAmount { get; set; }
    public virtual int NumberOfInvoices { get; set; }

    public override bool Equals(object obj)
    {
        var t = obj as ReconciliationReportLineItem;
        if (t == null) return false;
        return
            t.ID == this.ID
            && t.Category == this.Category;
    }

    public override int GetHashCode()
    {
        return string.Format("{0}{1}{2:yyyyMMddHHmmss}{3}{4}{5}{6}",
            this.FileName, this.BatchType, this.CreatedTimeStamp,
            this.NumberOfInvoices, this.LocalAmount, this.Amount,
            this.Currency).GetHashCode();
    }
}

and my fluent mapping file as such:

public class ReconciliationReportLineItemMapping : ClassMap<ReconciliationReportLineItem>
{
    public ReconciliationReportLineItemMapping()
    {
        Table("ReconciliationReportLineItem");

        CompositeId()
            .KeyProperty(x => x.ID, "id")
            .KeyProperty(x => x.Category, "category");

        Map(x => x.FileName)
            .Length(500)
            .Nullable()
            .Index("ixDatroseReconciliationReportLineItemFileName");

        Map(x => x.Amount)
            .Not.Nullable();

        Map(x => x.BatchType)
            .Not.Nullable();

        Map(x => x.CreatedTimeStamp)
            .Index("ixDatroseReconciliationReportLineItemCreatedTimeStamp")
            .Not.Nullable();

        Map(x => x.Currency)
            .Not.Nullable();

        Map(x => x.LocalAmount)
            .Not.Nullable();

        Map(x => x.NumberOfInvoices)
            .Not.Nullable();
    }
}

I populate the object, try to commit it, and I get an error like so:

ERROR: 23505: duplicate key value violates unique constraint "reconciliationreportlineitem_pkey"

The error sql shows that the members of the composite key (which were preset) are set to zero:

INSERT INTO ReconciliationReportLineItem (FileName, Amount, BatchType, CreatedTimeStamp, Currency, LocalAmount, NumberOfInvoices, id, category) 
VALUES (((NULL)::text), ((E'1065.47')::numeric), ((E'X200 batch created 20121027')::text), ((E'2012-10-27 08:39:00.000000')::timestamp), ((E'USD')::text), ((E'1065.47')::numeric), ((7)::int4), ((0)::int4), ((0)::int4))

…but I had specified the values before I tried to merge the records into the table. With a breakpoint, I was able to verify the objects did in fact have values before committing the session transaction.

What am I doing wrong? I need to specify the values of the keys.

Answer 1

I don’t remember what the NHibernate default key generator is but try adding this to tell NH you’re going to assign the keys using a component as an identifier. There aren’t many examples for this approach but this forum post is partial one. Here is the updated code:

// snipped >%

CompositeId()
    .ComponentCompositeIdentifier<ReconciliationReportLineItemKey>
       (rrli => rrli.Key)
    .KeyProperty(k => k.Key.Id)
    .KeyProperty(k => k.Key.Category);

// snipped >%

You’ll need to add a new class for the key to make assignments for:

public class ReconciliationReportLineItemKey
{
    public virtual int Id { get; set; }
    public virtual int Category { get; set; }
}

and also add a property the component to your entity class:

public class ReconciliationReportLineItem
{
    // snipped >%

    public virtual ReconciliationReportLineItemKey Key { get; set; }

    // snipped >%
}