CREATE TRIGGER tr_SalesHistory ON SalesHistory
FOR UPDATE
AS
BEGIN
  DECLARE @FldsUpdated XML, @ColumnsUpdated VARBINARY(100)
  SET @ColumnsUpdated = COLUMNS_UPDATED()
  SET @FldsUpdated =
    (
      SELECT COLUMN_NAME AS Name
      FROM TRS.INFORMATION_SCHEMA.COLUMNS Field
      WHERE TABLE_NAME = 'SalesHistory'
      AND sys.fn_IsBitSetInBitmask
        (
        @ColumnsUpdated,
        COLUMNPROPERTY
          (
            OBJECT_ID( TABLE_SCHEMA + '.' + TABLE_NAME ),
            COLUMN_NAME,
            'ColumnID'
          )
        ) <> 0
      FOR XML AUTO, ROOT('Fields')
    )     

  INSERT INTO SalesHistoryAudit
  (
    SaleID,
    Product,
    SaleDate,
    SalePrice,
    ColumnsUpdated
  )
  SELECT
    SaleID,
    Product,
    SaleDate,
    SalePrice,
    @FldsUpdated
  FROM INSERTED
END
GO