I'm trying to create a table to map some customize permissions for members to umbracoContentNodes...

However I cannot use the ForeignKey attribute to reference the cmsContent table because the ContentDto table and all the Dto tables in the RDBMS namespace are marked internal.

Is there another way to do it without using the ForeignKey attribute on my poco?

I know that this could cause deletes to fail in umbraco code, but I am handling that with a Content Deleting event. Right before a content node is deleted, code checks if there is an entry in my table and deletes the referring table entry from my table to prevent the delete in umbraco from failing on my foreign key constraint.

The way I am getting around this at the moment is to reproduce the ContentDto class, just what I need for the referrences...

/// <summary>
/// This Poco represents the table TLCKB will create to keep track of what permissions Members have to TLCKB Content Nodes
/// </summary>
[TableName("TLCKB_NodeMemberPermissions")]
[PrimaryKey("id", autoIncrement = true)]
public class NodeMemberPermissions
{
    #region Foreign Key Tables
    /// <summary>
    /// These are here only to allow creating foreign keys, Umbraco has all these tables internal so we can map foreign keys to them without doing this...
    /// </summary>
    [ExplicitColumns, TableName("umbracoNode"), PrimaryKey("id")]
    internal class NodeDto 
    {
        [PrimaryKeyColumn(Name="PK_structure", IdentitySeed=0x41a), Column("id")]
        public int NodeId { get; set; }
    }

    [ExplicitColumns, PrimaryKey("nodeId", autoIncrement = false), TableName("cmsMember")]
    internal class MemberDto
    {
        [PrimaryKeyColumn(AutoIncrement = false), ForeignKey(typeof(ContentDto), Column = "nodeId"), ForeignKey(typeof(NodeDto)), Column("nodeId")]
        public int NodeId { get; set; }
    }

    [PrimaryKey("pk"), TableName("cmsContent"), ExplicitColumns]
    internal class ContentDto
    {
        [Column("pk"), PrimaryKeyColumn]
        public int PrimaryKey { get; set; }
    }
    #endregion

    [Column("id")]
    [PrimaryKeyColumn(AutoIncrement = true)]
    public int Id { get; set; }

    [Column("nodeId"), ForeignKey(typeof(ContentDto))]
    public int ContentNodeId { get; set; }

    [Column("NodeType")]
    public TLCKBNodeType NodeType { get; set; }

    [Column("MemberId"), ForeignKey(typeof(MemberDto))]
    public int? MemberId { get; set; }

    [Column("Role")]
    public string Role { get; set; }

    [Column("Permissions")]
    public ulong Permissions { get; set; }        
}

I haven't tested this yet,

But when created my table should prevent inserts that don't exist in the cmsContent or cmsMember table.