I have the data table below. I would like to change the data table to transform the data table into the one next to it. How can I do this?
The reason why i would lik
Create a new table, with reversed dimensions from what you previously had, and assign the previous columns to the new rows, and the old rows to the new columns.
eg:
oldCol1 -> newRow1
oldCol2 -> newRow2
oldCol3 -> newRow3
oldCol4 -> newRow4
oldRow1 -> newCol1
oldCol2 -> newCol2
oldvar[a][b] -> newvar[b][a]
and the list goes on, assumming that you are going from
col1 || col2 || col3 || col4
row1 ||[a][b]||[c][d]||[e][f]
row2 ||[g][h]||[i][j]||[k][l]
to
row1 || col1 || col2
row2 ||[a][b]||[g][h]
row3 ||[c][d]||[i][j]
row4 ||[e][f]||[k][l]
.NET does not include a method to transpose data tables. You have to make your own. This website has a tutorial on an example transpose method. I will copy and paste the code snippet below:
private DataTable Transpose(DataTable dt)
{
DataTable dtNew = new DataTable();
//adding columns
for(int i=0; i<=dt.Rows.Count; i++)
{
dtNew.Columns.Add(i.ToString());
}
//Changing Column Captions:
dtNew.Columns[0].ColumnName = " ";
for(int i=0; i<dt.Rows.Count; i++)
{
//For dateTime columns use like below
dtNew.Columns[i+1].ColumnName = Convert.ToDateTime(dt.Rows[i].ItemArray[0].ToString()).ToString("MM/dd/yyyy");
//Else just assign the ItermArry[0] to the columnName prooperty
}
//Adding Row Data
for(int k=1; k<dt.Columns.Count; k++)
{
DataRow r = dtNew.NewRow();
r[0] = dt.Columns[k].ToString();
for(int j=1; j<=dt.Rows.Count; j++)
r[j] = dt.Rows[j-1][k];
dtNew.Rows.Add(r);
}
return dtNew;
}
DataTable newDt = new DataTable();
//Select indexes
var indexes = dt.Rows.Cast<DataRow>().Select(row => dt.Rows.IndexOf(row));
//Select the columns
var newCols = indexes.Select(i => "Row" + i);
//Add columns
foreach(var newCol in newCols)
{
newDt.Add(newCol);
}
//Select rows
var newRows = dt.Rows.Cast<DataColumn>().Select(col =>
{
row = newDt.NewRow();
foreach(int i in indexes)
{
row[i] = dt.Rows[i][col.Name];
}
return row;
});
//Add row to new datatable
foreach(var row in newRows)
{
newDt.Add(row);
}