How to create simple and advanced pivot tables in C# and ASP.NET

SELECT
SalesPeople.FullName AS [Sales Person]
, Products.FullName AS [Product]
, SUM(Sales.SalesAmount) AS [Sale Amount]
, SUM(Sales.Qty) AS [Quantity]
FROM
Sales
JOIN
SalesPeople WITH (NOLOCK)
ON SalesPeople.SalesPersonID = Sales.SalesPersonID
JOIN
Products WITH (NOLOCK)
ON Products.ProductCode = Sales.ProductCode
GROUP BY
SalesPeople.FullName
, Products.FullName

#region Variables
private DataTable _DataTable;
private string _CssTopHeading;
private string _CssSubHeading;
private string _CssLeftColumn;
private string _CssItems;
private string _CssTotals;
private string _CssTable;
#endregion Variables
#region Constructors
public Pivot(DataTable dataTable)
{
Init();
_DataTable = dataTable;
}
#endregion Constructors

private string FindValue(string xAxisField, string xAxisValue, string yAxisField, string yAxisValue, string zAxisField)
{
string zAxisValue = "";
try
{
foreach (DataRow row in _DataTable.Rows)
{
if (Convert.ToString(row[xAxisField]) == xAxisValue && Convert.ToString(row[yAxisField]) == yAxisValue)
{
zAxisValue = Convert.ToString(row[zAxisField]);
break;
}
}
}
catch
{
throw;
}
return zAxisValue;
}

private string[] FindValues(string xAxisField, string xAxisValue, string yAxisField, string yAxisValue, string[] zAxisFields)
{
int zAxis = zAxisFields.Length;
if (zAxis < 1)
zAxis++;
string[] zAxisValues = new string[zAxis];
//set default values
for (int i = 0; i <= zAxisValues.GetUpperBound(0); i++)
{
zAxisValues[i] = "0";
}
try
{
foreach (DataRow row in _DataTable.Rows)
{
if (Convert.ToString(row[xAxisField]) == xAxisValue && Convert.ToString(row[yAxisField]) == yAxisValue)
{
for (int z = 0; z < zAxis; z++)
{
zAxisValues[z] = Convert.ToString(row[zAxisFields[z]]);
}
break;
}
}
}
catch
{
throw;
}
return zAxisValues;
}

private void MainHeaderTopCellStyle(HtmlTableCell cell)
{
if (_CssTopHeading == "")
{
cell.Style.Add("font-family", "tahoma");
cell.Style.Add("font-size", "10pt");
cell.Style.Add("font-weight", "normal");
cell.Style.Add("background-color", "black");
cell.Style.Add("color", "white");
cell.Style.Add("text-align", "center");
}
else
cell.Attributes.Add("Class", _CssTopHeading);
}

/// <summary>
/// Creates an advanced 3D Pivot table.
/// </summary>
/// <param name="xAxisField">The main heading at the top of the report.</param>
/// <param name="yAxisField">The heading on the left of the report.</param>
/// <param name="zAxisFields">The sub heading at the top of the report.</param>
/// <returns>HtmlTable Control.</returns>
public HtmlTable PivotTable(string xAxisField, string yAxisField, string[] zAxisFields)
{
HtmlTable table = new HtmlTable();
//style table
TableStyle(table);
/*
* The x-axis is the main horizontal row.
* The z-axis is the sub horizontal row.
* The y-axis is the left vertical column.
*/
try
{
//get distinct xAxisFields
ArrayList xAxis = new ArrayList();
foreach (DataRow row in _DataTable.Rows)
{
if (!xAxis.Contains(row[xAxisField]))
xAxis.Add(row[xAxisField]);
}
//get distinct yAxisFields
ArrayList yAxis = new ArrayList();
foreach (DataRow row in _DataTable.Rows)
{
if (!yAxis.Contains(row[yAxisField]))
yAxis.Add(row[yAxisField]);
}
//create a 2D array for the y-axis/z-axis fields
int zAxis = zAxisFields.Length;
if (zAxis < 1)
zAxis = 1;
string[,] matrix = new string[(xAxis.Count * zAxis), yAxis.Count];
string[] zAxisValues = new string[zAxis];
for (int y = 0; y < yAxis.Count; y++) //loop thru y-axis fields
{
//rows
for (int x = 0; x < xAxis.Count; x++) //loop thru x-axis fields
{
//main columns
//get the z-axis values
zAxisValues = FindValues(xAxisField, Convert.ToString(xAxis[x])
, yAxisField, Convert.ToString(yAxis[y]), zAxisFields);
for (int z = 0; z < zAxis; z++) //loop thru z-axis fields
{
//sub columns
matrix[(((x + 1) * zAxis - zAxis) + z), y] = zAxisValues[z];
}
}
}
//calculate totals for the y-axis
decimal[] yTotals = new decimal[(xAxis.Count * zAxis)];
for (int col = 0; col < (xAxis.Count * zAxis); col++)
{
yTotals[col] = 0;
for (int row = 0; row < yAxis.Count; row++)
{
yTotals[col] += Convert.ToDecimal(matrix[col, row]);
}
}
//calculate totals for the x-axis
decimal[,] xTotals = new decimal[zAxis, (yAxis.Count + 1)];
for (int y = 0; y < yAxis.Count; y++) //loop thru the y-axis
{
int zCount = 0;
for (int z = 0; z < (zAxis * xAxis.Count); z++) //loop thru the z-axis
{
xTotals[zCount, y] += Convert.ToDecimal(matrix[z, y]);
if (zCount == (zAxis - 1))
zCount = 0;
else
zCount++;
}
}
for (int xx = 0; xx < zAxis; xx++) //Grand Total
{
for (int xy = 0; xy < yAxis.Count; xy++)
{
xTotals[xx, yAxis.Count] += xTotals[xx, xy];
}
}
//Build HTML Table
//Append main row (x-axis)
HtmlTableRow mainRow = new HtmlTableRow();
mainRow.Cells.Add(new HtmlTableCell());
for (int x = 0; x <= xAxis.Count; x++) //loop thru x-axis + 1
{
HtmlTableCell cell = new HtmlTableCell();
cell.ColSpan = zAxis;
if (x < xAxis.Count)
cell.InnerText = Convert.ToString(xAxis[x]);
else
cell.InnerText = "Grand Totals";
//style cell
MainHeaderTopCellStyle(cell);
mainRow.Cells.Add(cell);
}
table.Rows.Add(mainRow);
//Append sub row (z-axis)
HtmlTableRow subRow = new HtmlTableRow();
subRow.Cells.Add(new HtmlTableCell());
subRow.Cells[0].InnerText = yAxisField;
//style cell
SubHeaderCellStyle(subRow.Cells[0]);
for (int x = 0; x <= xAxis.Count; x++) //loop thru x-axis + 1
{
for (int z = 0; z < zAxis; z++)
{
HtmlTableCell cell = new HtmlTableCell();
cell.InnerText = zAxisFields[z];
//style cell
SubHeaderCellStyle(cell);
subRow.Cells.Add(cell);
}
}
table.Rows.Add(subRow);
//Append table items from matrix
for (int y = 0; y < yAxis.Count; y++) //loop thru y-axis
{
HtmlTableRow itemRow = new HtmlTableRow();
for (int z = 0 ; z <= (zAxis * xAxis.Count); z++) //loop thru z-axis + 1
{
HtmlTableCell cell = new HtmlTableCell();
if (z == 0)
{
cell.InnerText = Convert.ToString(yAxis[y]);
//style cell
MainHeaderLeftCellStyle(cell);
}
else
{
cell.InnerText = Convert.ToString(matrix[(z-1), y]);
//style cell
ItemCellStyle(cell);
}
itemRow.Cells.Add(cell);
}
//append x-axis grand totals
for (int z = 0; z < zAxis; z++)
{
HtmlTableCell cell = new HtmlTableCell();
cell.InnerText = Convert.ToString(xTotals[z, y]);
//style cell
TotalCellStyle(cell);
itemRow.Cells.Add(cell);
}
table.Rows.Add(itemRow);
}
//append y-axis totals
HtmlTableRow totalRow = new HtmlTableRow();
for (int x = 0; x <= (zAxis * xAxis.Count); x++)
{
HtmlTableCell cell = new HtmlTableCell();
if (x == 0)
cell.InnerText = "Totals";
else
cell.InnerText = Convert.ToString(yTotals[x-1]);
//style cell
TotalCellStyle(cell);
totalRow.Cells.Add(cell);
}
//append x-axis/y-axis totals
for (int z = 0; z < zAxis; z++)
{
HtmlTableCell cell = new HtmlTableCell();
cell.InnerText = Convert.ToString(xTotals[z, xTotals.GetUpperBound(1)]);
//style cell
TotalCellStyle(cell);
totalRow.Cells.Add(cell);
}
table.Rows.Add(totalRow);
}
catch
{
throw;
}
return table;
}

public DataTable DataTableForTesting
{
get
{
DataTable dt = new DataTable("Sales Table");
dt.Columns.Add("Sales Person");
dt.Columns.Add("Product");
dt.Columns.Add("Quantity");
dt.Columns.Add("Sale Amount");
dt.Rows.Add(new object[] { "John", "Pens", 200, 350.00 });
dt.Rows.Add(new object[] { "John", "Pencils", 400, 500.00 });
dt.Rows.Add(new object[] { "John", "Notebooks", 100, 300.00 });
dt.Rows.Add(new object[] { "John", "Rulers", 50, 100.00 });
dt.Rows.Add(new object[] { "John", "Calculators", 120, 1200.00 });
dt.Rows.Add(new object[] { "John", "Back Packs", 75, 1500.00 });
dt.Rows.Add(new object[] { "Jane", "Pens", 225, 393.75 });
dt.Rows.Add(new object[] { "Jane", "Pencils", 335, 418.75 });
dt.Rows.Add(new object[] { "Jane", "Notebooks", 200, 600.00 });
dt.Rows.Add(new object[] { "Jane", "Rulers", 75, 150.00 });
dt.Rows.Add(new object[] { "Jane", "Calculators", 80, 800.00 });
dt.Rows.Add(new object[] { "Jane", "Back Packs", 97, 1940.00 });
dt.Rows.Add(new object[] { "Sally", "Pens", 202, 353.50 });
dt.Rows.Add(new object[] { "Sally", "Pencils", 303, 378.75 });
dt.Rows.Add(new object[] { "Sally", "Notebooks", 198, 600.00 });
dt.Rows.Add(new object[] { "Sally", "Rulers", 98, 594.00 });
dt.Rows.Add(new object[] { "Sally", "Calculators", 80, 800.00 });
dt.Rows.Add(new object[] { "Sally", "Back Packs", 101, 2020.00 });
dt.Rows.Add(new object[] { "Sarah", "Pens", 112, 196.00 });
dt.Rows.Add(new object[] { "Sarah", "Pencils", 245, 306.25 });
dt.Rows.Add(new object[] { "Sarah", "Notebooks", 198, 594.00 });
dt.Rows.Add(new object[] { "Sarah", "Rulers", 50, 100.00 });
dt.Rows.Add(new object[] { "Sarah", "Calculators", 66, 660.00 });
dt.Rows.Add(new object[] { "Sarah", "Back Packs", 50, 2020.00 });
return dt;
}
}

protected void Page_Load(object sender, EventArgs e)
{
//Advanced Pivot
Pivot advPivot = new Pivot(DataTableForTesting);
HtmlTable advancedPivot = advPivot.PivotTable("Sales Person", "Product", new string[] { "Sale Amount", "Quantity" });
div1.Controls.Add(advancedPivot);
//Simple Pivot
Pivot pivot = new Pivot(DataTableForTesting);
//override default style with css
pivot.CssTopHeading = "Heading";
pivot.CssLeftColumn = "LeftColumn";
pivot.CssItems = "Items";
pivot.CssTotals = "Totals";
pivot.CssTable = "Table";
HtmlTable simplePivot = pivot.PivotTable("Product", "Sales Person", "Sale Amount");
div2.Controls.Add(simplePivot);
}