我正在尝试使用以下代码来创建 PIVOT，但它不起作用。
它给了我编译时错误。我不知道 linq 所以无法使用它。
请帮忙 ：
DataTable Pivot(DataTable dt, DataColumn pivotColumn, DataColumn pivotValue) {
// find primary key columns
//(i.e. everything but pivot column and pivot value)
DataTable temp = dt.Copy();
temp.Columns.Remove( pivotColumn.ColumnName );
temp.Columns.Remove( pivotValue.ColumnName );
string[] pkColumnNames = temp.Columns.Cast(<DataColumn>)
.Select( c => c.ColumnName )
.ToArray();
// prep results table
DataTable result = temp.DefaultView.ToTable(true, pkColumnNames).Copy();
result.PrimaryKey = result.Columns.Cast(<DataColumn>).ToArray();
dt.AsEnumerable()
.Select(r =>; r[pivotColumn.ColumnName].ToString())
.Distinct().ToList()
.ForEach (c => result.Columns.Add(c, pivotColumn.DataType));
// load it
foreach( DataRow row in dt.Rows ) {
// find row to update
DataRow aggRow = result.Rows.Find(
pkColumnNames
.Select( c => row[c] )
.ToArray() );
// the aggregate used here is LATEST
// adjust the next line if you want (SUM, MAX, etc...)
aggRow[row[pivotColumn.ColumnName].ToString()] = row[pivotValue.ColumnName];
}
return result;
}
代码来自： http: //michaeljswart.com/2011/06/forget-about-pivot/
此外，它尝试使用以下代码，它运行良好，除了它没有给出值列的总和
public DataTable GetInversedDataTable(DataTable table, string columnX, string columnY, string columnZ, string nullValue, bool sumValues)
{
//Create a DataTable to Return
DataTable returnTable = new DataTable();
DataTable tempTable = table.Clone();
if (string.IsNullOrEmpty(columnX))
{
columnX = table.Columns[0].ColumnName;
}
tempTable.Columns.Remove(columnX);
//Add a Column at the beginning of the table
//returnTable.Columns.Add(columnY);
returnTable = tempTable.Clone();
//Read all DISTINCT values from columnX Column in the provided DataTale
List<string> columnXValues = new List<string>();
foreach (DataRow dr in table.Rows)
{
string columnXTemp = dr[columnX].ToString();
if (!columnXValues.Contains(columnXTemp))
{
//Read each row value, if it's different from others provided, add to the list of values and creates a new Column with its value.
columnXValues.Add(columnXTemp);
returnTable.Columns.Add(columnXTemp);
}
}
//Verify if Y and Z Axis columns re provided
if (!string.IsNullOrEmpty(columnY) && !string.IsNullOrEmpty(columnZ))
{
//Read DISTINCT Values for Y Axis Column
List<string> columnYValues = new List<string>();
foreach (DataRow dr in table.Rows)
{
if (!columnYValues.Contains(dr[columnY].ToString()))
{
columnYValues.Add(dr[columnY].ToString());
}
}
//Loop all Column Y Distinct Value
foreach (string columnYValue in columnYValues)
{
//Creates a new Row
DataRow drReturn = returnTable.NewRow();
drReturn[0] = columnYValue;
//foreach column Y value, The rows are selected distincted
DataRow[] rows = table.Select((columnY + "='") + columnYValue + "'");
//Read each row to fill the DataTable
foreach (DataRow dr in rows)
{
string rowColumnTitle = dr[columnX].ToString();
//Read each column to fill the DataTable
foreach (DataColumn dc in returnTable.Columns)
{
if (dc.ColumnName == rowColumnTitle)
{
//If Sum of Values is True it try to perform a Sum
//If sum is not possible due to value types, the value displayed is the last one read
if (sumValues)
{
try
{
drReturn[rowColumnTitle] = Convert.ToDecimal(drReturn[rowColumnTitle]) + Convert.ToDecimal(dr[columnZ]);
}
catch
{
drReturn[rowColumnTitle] = dr[columnZ];
}
}
else
{
drReturn[rowColumnTitle] = dr[columnZ];
}
}
}
}
returnTable.Rows.Add(drReturn);
}
}
else
{
throw new Exception("The columns to perform inversion are not provided");
}
//if a nullValue is provided, fill the datable with it
if (!string.IsNullOrEmpty(nullValue))
{
foreach (DataRow dr in returnTable.Rows)
{
foreach (DataColumn dc in returnTable.Columns)
{
if (string.IsNullOrEmpty(dr[dc.ColumnName].ToString()))
{
dr[dc.ColumnName] = nullValue;
}
}
}
}
return returnTable;
}
GetInversedDataTable(dtNormal, "Dated", "OrderStatus", "Qty", " ", true);
请帮忙 ：）