/// <summary>
		/// Constructs a column.
		/// </summary>
		/// <param name="context">The <see cref="IMansionContext"/>.</param>
		/// <param name="table">The <see cref="Table"/>.</param>
		/// <param name="propertyName">The name of the property.</param>
		public NodeStatusPropertyColumn(IMansionContext context, Table table, string propertyName) : base(propertyName)
		{
			// validate arguments
			if (table == null)
				throw new ArgumentNullException("table");

			// create the columns
			var approvedColumn = BooleanPropertyColumn.CreateBooleanColumn(context, "approved", "approved", new PropertyBag
			                                                                                                {
			                                                                                                	{"allowNullValue", false},
			                                                                                                	{"defaultValue", true}
			                                                                                                });
			var publicationDateColumn = DateTimePropertyColumn.CreateDateTimeColumn(context, "publicationDate", "publicationDate", new PropertyBag
			                                                                                                                       {
			                                                                                                                       	{"allowNullValue", false},
			                                                                                                                       	{"expression", "{NotNull( Column.value, Now() )}"}
			                                                                                                                       });
			var expirationDateColumn = DateTimePropertyColumn.CreateDateTimeColumn(context, "expirationDate", "expirationDate", new PropertyBag
			                                                                                                                    {
			                                                                                                                    	{"allowNullValue", false},
			                                                                                                                    	{"expression", "{NotNull( Column.value, MaxSqlDate() )}"}
			                                                                                                                    });
			var archivedColumn = BooleanPropertyColumn.CreateBooleanColumn(context, "archived", "archived", new PropertyBag
			                                                                                                {
			                                                                                                	{"allowNullValue", false},
			                                                                                                	{"defaultValue", false}
			                                                                                                });

			// add marker columns
			table.Add(approvedColumn);
			table.Add(publicationDateColumn);
			table.Add(expirationDateColumn);
			table.Add(archivedColumn);
		}
		/// <summary>
		/// Constructs a column.
		/// </summary>
		/// <param name="table">The <see cref="Table"/>.</param>
		/// <param name="propertyName">The name of the property.</param>
		public NodePointerPropertyColumn(Table table, string propertyName) : base(propertyName, propertyName, 150)
		{
			// validate arguments
			if (table == null)
				throw new ArgumentNullException("table");

			// add marker columns
			table.Add(new VirtualColumn("name"));
			table.Add(new VirtualColumn("type"));
			table.Add(new VirtualColumn("depth"));
			table.Add(new VirtualColumn("parentId"));
			table.Add(new VirtualColumn("parentPointer"));
			table.Add(new VirtualColumn("parentPath"));
			table.Add(new VirtualColumn("parentStructure"));
		}