EPPlus pivot tables/charts

Question

I've been using EPPlus for .net for a while now but only for simple data manipulation. Are there any examples somewhere on how to use it to create pivot tables/charts? It seems to support it as I can see PivotTable in the intellisense but just unsure on the syntax.

I could only find the likes of pie/bar charts in the samples provided.

Answer 1

I've produced a similar solution from Tim's Answer. First, I defined a simple interface that I use as part of my export methods:

public interface IPivotTableCreator
{
    void CreatePivotTable(
        OfficeOpenXml.ExcelPackage pkg, // reference to the destination book
        string tableName,               // "tab" name used to generate names for related items
        string pivotRangeName);         // Named range in the Workbook refers to data
}

Then I implemented a simple class that hold the variable values and procedural code to do the work:

public class SimplePivotTable : IPivotTableCreator
{
    List<string> _GroupByColumns;
    List<string> _SummaryColumns;
    /// <summary>
    /// Constructor
    /// </summary>
    public SimplePivotTable(string[] groupByColumns, string[] summaryColumns)
    {
        _GroupByColumns = new List<string>(groupByColumns);
        _SummaryColumns = new List<string>(summaryColumns);
    }

    /// <summary>
    /// Call-back handler that builds simple PivatTable in Excel
    /// http://stackoverflow.com/questions/11650080/epplus-pivot-tables-charts
    /// </summary>
    public void CreatePivotTable(OfficeOpenXml.ExcelPackage pkg, string tableName, string pivotRangeName)
    {
        string pageName = "Pivot-" + tableName.Replace(" ", "");
        var wsPivot = pkg.Workbook.Worksheets.Add(pageName);
        pkg.Workbook.Worksheets.MoveBefore(PageName, tableName);

        var dataRange = pkg.Workbook./*Worksheets[tableName].*/Names[pivotRangeName];
        var pivotTable = wsPivot.PivotTables.Add(wsPivot.Cells["C3"], dataRange, "Pivot_" + tableName.Replace(" ", ""));
        pivotTable.ShowHeaders = true;
        pivotTable.UseAutoFormatting = true;
        pivotTable.ApplyWidthHeightFormats = true;
        pivotTable.ShowDrill = true;
        pivotTable.FirstHeaderRow = 1;  // first row has headers
        pivotTable.FirstDataCol = 1;    // first col of data
        pivotTable.FirstDataRow = 2;    // first row of data

        foreach (string row in _GroupByColumns)
        {
            var field = pivotTable.Fields[row];
            pivotTable.RowFields.Add(field);
            field.Sort = eSortType.Ascending;
        }

        foreach (string column in _SummaryColumns)
        {
            var field = pivotTable.Fields[column];
            ExcelPivotTableDataField result = pivotTable.DataFields.Add(field);
        }

        pivotTable.DataOnRows = false;
    }
}

Then I create an instance of my SimplePivotTable creator class:

IPivotTableCreator ptCreator = new SimplePivotTable(
    new string[] { "OrganizationTitle", "GroupingTitle", "DetailTitle" }, /* collapsible rows */
    new string[] { "Baseline", "Increase", "Decrease", "NetChange", "CurrentCount"}); /* summary columns */

I have a third class that currently exposes about six different methods to take one-or-more data sets (usually List objects) and turn each of the data sets into a worksheet of data with a named range for the data. Now, I'm adapting those export methods to allow me to generate Pivot Tables for any/all of those export methods. They all do something like this:

OfficeOpenXml.ExcelPackage pkg = new ExcelPackage();
ExportCollectionToExcel(pkg, tableName, dataset);   // Create worksheet filled with data
                                                    // Creates a NamedRange of data
ptCreator.CreatePivotTable(pkg, tableName, GetPivotRangeName(tableName));

By using an interface, I leave open more opportunities (I think) to generate, for example, a different pivot table for multiple sheets. My basic SimplePivotTable class just used for a single table with some specific assumptions, but it wouldn't be hard to put the configuration data into a dictionary keyed to the Table names.

Hope that helps someone.