Question

So, I have an Invoice object like so:

public class Invoice
{
    public virtual long InvoiceId { get; set; }

    public virtual string InvoiceNumber{ get; set; }
    public virtual Customer Customer { get; set; }
    public virtual Site Site { get; set; }

    public virtual IList<InvoiceLineItem> LineItems { get; set; }
    public virtual IList<InvoicePayment> Transactions { get; set; }
}

Then, I have an invoice line item like this

public class InvoiceLineItem
{
    public virtual long InvoiceLineItemId { get; set; }

    public virtual Invoice Invoice{ get; set; }
}

And finally, an invoice Payment

public class InvoicePayment
{
    public virtual long InvoicePaymentId { get; set; }

    public virtual Invoice Invoice{ get; set; }
}

The problem is this, in my underlying schema for InvoicePayment, I have InvoiceNumber, SiteId (to the Site object), and CustomerId (to the Customer object).

In InvoiceLineItem, I have InvoiceId linking back to Invoice.

So, my mapping for Invoice looks something like this:

public sealed class InvoiceMap : ClassMap<Invoice>
{
    public InvoiceMap()
    {
        Table("InvoiceView");

        Id(x => x.InvoiceId).GeneratedBy.Identity();


        Map(x => x.InvoiceNumber);

        References<Site>(x => x.Site, "SiteId");
        References<Customer>(x => x.Customer, "CustomerId");

        HasMany<InvoiceLineItem>(x => x.LineItems)
            .Inverse();

        HasMany<InvoicePayment>(x => x.Transactions)
            .KeyColumns.Add("SiteId")
            .KeyColumns.Add("EPayCustomerId")
            .KeyColumns.Add("InvoiceNumber")
            .Inverse();
    }
}

Line Items mapping

public class InvoiceLineItemMap : ClassMap<InvoiceLineItem>
{
    public InvoiceLineItemMap()
    {
        Table("InvoiceLineItems");

        Id(x => x.InvoiceLineItemId).GeneratedBy.Identity();

        References<FTNI.Core.Model.Invoice.Invoice>(x => x.Invoice, "InvoiceId");
    }
}

And finally my Invoice payments mapping

public class InvoicePaymentMap : ClassMap<InvoicePayment>
{
    public InvoicePaymentMap()
    {
        Table("InvoicePayments");

        Id(x => x.InvoicePaymentId).GeneratedBy.Identity();

        CompositeId()
            .KeyProperty(x => x.Site, "SiteId")
            .KeyProperty(x => x.Customer, "CustomerId")
            .KeyProperty(x => x.InvoiceNumber);

        References<Site>(x => x.Site, "SiteId");
        References<EPayCustomer>(x => x.Customer, "CustomerId");

        References<FTNI.Core.Model.Invoice.Invoice>(x => x.Invoice)
            .Columns("SiteId", "CustomerId", "InvoiceNumber")
            .Nullable();

    }
}

So, as it is, I am getting an error

Foreign key (FKE9F746C567E71B3F:InvoiceLineItems [InvoiceId])) must have same number of columns as the referenced primary key (InvoiceView [SiteId, CustomerId, InvoiceNumber])

How can I adjust my mappings so I join to the invoice payments on a composite id and the line items on the identity column?

Answer 1

the error message looks a bit weird. I would expect a CompositeId()... in InvoiceMap to produce this error.

The error stems from the fact that each entity can only have 1 Id and the call to CompositeId overrides the previous call to Id, hence the Id of Invoice is the CompositeId and a single Column in InvoiceLineItem doesnt match.

try the following:

public class Invoice
{
    public virtual long InvoiceId { get; set; }

    public virtual InvoiceIdentity Identity { get; set; }

    public virtual IList<InvoiceLineItem> LineItems { get; set; }
    public virtual IList<InvoicePayment> Transactions { get; set; }

}

public class InvoiceIdentity
{
    public virtual string InvoiceNumber{ get; private set; }
    public virtual Customer Customer { get; private set; }
    public virtual Site Site { get; private set; }
    public Identity(string invoicenumber, Customer customer, Site site)
    {
        InvoiceNumber = invoicenumber;
        Customer = customer;
        Site = site;
    }
}

public sealed class InvoiceMap : ClassMap<Invoice>
{
    public InvoiceMap()
    {
        Table("InvoiceView");

        Id(x => x.InvoiceId).GeneratedBy.Identity();


        Component(x => x.Identity, c =>
        {
            c.Map(x => x.InvoiceNumber);

            c.References(x => x.Site, "SiteId");
            c.References(x => x.Customer, "CustomerId");
        });

        HasMany(x => x.LineItems)
            .Inverse();

        HasMany(x => x.Transactions)
            .PropertyRef(i => i.Identity)
            .KeyColumns.Add("SiteId", "EPayCustomerId", "InvoiceNumber")
            .Inverse();
    }
}

public class InvoicePaymentMap : ClassMap<InvoicePayment>
{
    public InvoicePaymentMap()
    {
        Table("InvoicePayments");

        Id(x => x.InvoicePaymentId).GeneratedBy.Identity();

        References(x => x.Invoice)
            .Columns("SiteId", "CustomerId", "InvoiceNumber")
            .PropertyRef(i => i.Identity)
            .Nullable();

    }
}