title: Open XML SDK 2.0 - how to update a cell in a spreadsheet?
body: <p>I want to update a cell in a spreadsheet that is used by a chart, using the Open XML SDK 2.0 (CTP). All the code samples I have found insert new cells. I am struggling with retrieving the right worksheet.</p>
  
  <pre><code>public static void InsertText(string docName, string text, uint rowIndex, 
    string columnName)
  {
    // Open the document for editing.
    using (SpreadsheetDocument spreadSheet = 
      SpreadsheetDocument.Open(docName, true))
    {
      Workbook workBook = spreadSheet.WorkbookPart.Workbook;
  
      WorksheetPart worksheetPart = workBook.WorkbookPart.
        WorksheetParts.First();
  
      SheetData sheetData = worksheetPart.Worksheet.
        GetFirstChild&lt;SheetData&gt;();
  
      // If the worksheet does not contain a row with the specified
      // row index, insert one.
      Row row;
  
      if (sheetData.Elements&lt;Row&gt;().Where(
        r =&gt; r.RowIndex == rowIndex).Count() != 0)
        // At this point I am expecting a match for a row that exists
        // in sheet1 but I am not getting one
  </code></pre>
  
  <p>When I navigate the tree in Visual Studio, I am seeing three sheets, but none of them has any children. What am I missing?</p>