The ObjectMapper .NET Project

The [GroupBy] attribute can be used to group properties by there value. This property can only be used in projection classes.

    /// <summary>

    /// Groups the time entries by their project id

    /// </summary>

    public class TimeEntryGrouping

    {

        private DateTime minDate;

        private string project;

        /// <summary>

        /// Gets or sets the min date.

        /// </summary>

        /// <value>The first date.</value>

        [ProjectOntoProperty(typeof(TimeEntry), "StartDate")]

        [Min]

        public DateTime MinDate

        {

            get { return minDate; }

            set { minDate = value; }

        }

        /// <summary>

        /// Gets or sets the project.

        /// </summary>

        /// <value>The project.</value>

        [ProjectOntoProperty(typeof(TimeEntry), "ProjectId")]

        [GroupBy]

        public string Project

        {

            get { return project; }

            set { project = value;  }

        }

    }

Select the grouping:

                List<TimeEntryGrouping> result =

                    new List<TimeEntryGrouping>(

                        new ListAdapter<TimeEntryGrouping>(

                    mapper.FlatSelect(typeof(TimeEntryGrouping))));