从数据表中旋转值

Question

我有以下格式的数据表

Country Currency    Category    Value (Delivered)
AFRICA  USD         CONTAINER   100
AFRICA  USD         CONTAINER   100
AFRICA  USD         PLASTIC     100 
AFRICA  USD         PLASTIC     100 
AFRICA  USD         PLASTIC     100 
AFRICA  USD         PLASTIC     100 
AFRICA  USD         PLASTIC     100
AFRICA  USD         PLASTIC     100

我需要获得如下的值，

COUNTRY Currency    CONTAINER   PLASTIC     OTHERS
Africa  USD         200         600          0

意味着，塑料或容器以外的任何东西都需要添加到其他栏目中。

Answer 1

您可以为此目的使用NReco.PivotData nuget软件包：

DataTable tbl;  // lets assume this is your datatable
var pvtData = new PivotData(new[] {"Country", "Currency", "Category"}, new SumAggregatorFactory("Value (Delivered)") );
pvtData.ProcessData(new DataTableReader(tbl));
var pvtTbl = new PivotTable(
    new [] {"Country", "Currency"}, //rows
    new [] {"Category"}, //columns
    pvtData);

// use PivotTable class API to iterate through rows/columns and get the values
for (var r=0; r<pvtTbl.RowKeys.Length; r++) { 
    var rowKey = pvtTbl.RowKeys[r];
    for (var c=0; c<pvtTbl.ColumnKeys.Length; c++) {
        var cellValue = pvtTbl[r,c].Value;
        // do what you need: render HTML table, or export to CSV, or populate pivoted DataTable
    }
}

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