title: Opening an Excel (created with EPPLUS) with OleDB
body: <p>I have code from a colleague, this code creates a few excel sheets with Epplus. With my code I would like to add an database extract 10k+/- lines. Because of the large amount of data it takes too long with Epplus, because you need to write each cell. With OleDB it only takes a few seconds. But I can't open a previously created excel by Epplus with OleDB. Even with different connection strings.</p>
  
  <p>This my code works perfect if you separate the two code blocks.</p>
  
  <pre><code>var excelPath = "C:\\test_" + DateTime.Today.ToString("yyyyMMdd_") + DateTime.Now.ToString("hh") + DateTime.Now.Minute.ToString() + ".xlsx";
  using (ExcelPackage xlPackage = new ExcelPackage(new FileInfo(excelPath)))
  {
      ExcelWorksheet worksheet = xlPackage.Workbook.Worksheets.Add("Schedule V");
      worksheet.Cell(1, 1).Value = "test";
      xlPackage.Save();
      xlPackage.Dispose();
  }
  var strCn = "Provider=Microsoft.ACE.OLEDB.12.0;Data Source=" + excelPath + ";Extended Properties='Excel 12.0 Xml';";
  using (OleDbConnection conn = new OleDbConnection(strCn))
  {
      conn.Open();
      OleDbCommand cmd = new OleDbCommand();
      cmd.Connection = conn;
      cmd.CommandText = "CREATE TABLE [table1] (id INT, name VARCHAR, datecol DATE );";
      cmd.ExecuteNonQuery();
      cmd.CommandText = "INSERT INTO [table1](id,name,datecol) VALUES(1,'AAAA','2014-01-01');";
      cmd.ExecuteNonQuery();
      conn.Close();
  }
  </code></pre>
  
  <p>I tried the following connection strings but they all give the same error:</p>
  
  <blockquote>
    <p>OleDbException was unhandled, External table is not in the expected
    format.</p>
  </blockquote>
  
  <p>My diffrent connection string I tried:</p>
  
  <pre><code>var strCn = "Provider=Microsoft.ACE.OLEDB.12.0;Data Source=" + excelPath + ";Extended Properties='Excel 12.0';";
  var strCn = "Provider=Microsoft.ACE.OLEDB.12.0;Data Source=" + excelPath + ";Extended Properties='Excel 12.0 Xml';";
  var strCn = "Provider=Microsoft.ACE.OLEDB.12.0;Data Source=" + excelPath + ";Extended Properties='Excel 12.0 Xml;HDR=YES';";
  var strCn = "Provider=Microsoft.ACE.OLEDB.12.0;Data Source=" + excelPath + ";Extended Properties='Excel 12.0 Xml;HDR=YES;IMEX=1';";
  var strCn = "Provider=Microsoft.ACE.OLEDB.12.0;Data Source=" + excelPath + ";Extended Properties='Excel 8.0;HDR=YES';";
  var strCn = "Provider=Microsoft.Jet.OLEDB.4.0;Data Source=" + excelPath + ";Extended Properties='Excel 8.0;HDR=Yes;IMEX=1';";
  </code></pre>
  
  <p>What am I doing wrong here?</p>