Question

我试图调整记录列表，然后我遇到了这个：

 public static DataTable PivotTable<T, TColumn, TGroupRow, TRow, TData>(
        this System.Collections.Generic.IEnumerable<T> list,
        Func<T, TColumn> column,
        Expression<Func<T, TRow>> row,
        Func<IEnumerable<T>, TData> dataSelector)
        {
            DataTable table = new DataTable();
            var rowName = ((MemberExpression)row.Body).Member.Name;
            table.Columns.Add(new DataColumn(rowName));
            var columns = list.Select(column).Distinct();

            foreach (var col in columns)
                table.Columns.Add(new DataColumn(col.ToString()));

            var rows = list.GroupBy(row.Compile())
                             .Select(rowGroup => new
                             {
                                 Key = rowGroup.Key,
                                 Values = columns.GroupJoin(
                                     rowGroup,
                                     c => c,
                                     r => column(r),
                                     (c, columnGroup) => dataSelector(columnGroup))
                             });

            foreach (var rowVal in rows)
            {
                var dataRow = table.NewRow();
                var items = rowVal.Values.Cast<object>().ToList();

                items.Insert(0, rowVal.Key);

                dataRow.ItemArray = items.ToArray();
                table.Rows.Add(dataRow);
            }

            return table;
        }

这是此帖http://techbrij.com/pivot-c-array-datatable-convert-column-to-row-linq

提供的解决方案

我的客户端代码就像这样

var _dataSourceMatrix = //Some logic that get the DataTable records
var _departmentList = //Some logic that get the DataTable records

var _joinDataSourceDepartmentList = from a in _dataSourceMatrix.AsEnumerable()
                                                           join b in _departmentList.AsEnumerable()
                                                         on a.Field<int>("EntityID") equals b.Field<int>("DepartmentID")
                                                           select new { EntityName = b.Field<string>("Name"), Period = a.Field<string>("Period"), Value = a.Field<double>("Value"), EntityID = a.Field<int>("EntityID") };

_dataSourceMatrix = _joinDataSourceDepartmentList .OrderBy(x => x.Period).PivotTable(x => x.Period, x => x.EntityName, x => x.Sum(y => y.Value));

但是，这只是3列字段：可以使用Period，EntityName和Value。我也希望使用EntityID。它应该是具有EntityName的记录分组的关键之一。有没有办法修改数据透视表功能？

要实现的目标应该是这样的：

EntityName Period1, Period2, Period3, EntityID
A            Value1   Value2  Value3    1
B            Value1   Value2  Value3    2

带有更多列的数据透视表

0 个答案: