读取Excel文件的特定列并使用C＃添加到查询

Question

I want to read a particular column from an excel file and pick each value and put it into a query using c#. I have written a code to read an excel file and show it in datagridview but got stuck while reading a particular column.

Need some help. Below is the code.

private void button1_Click(object sender, EventArgs e)
{
    using (OpenFileDialog ofd = new OpenFileDialog() { Filter = "Excel Workbook|*.xls", ValidateNames = true })
    {
        if (ofd.ShowDialog() == DialogResult.OK)
        {
            FileStream fs = File.Open(ofd.FileName, FileMode.Open, FileAccess.Read);
            IExcelDataReader reader = ExcelReaderFactory.CreateBinaryReader(fs);
            var conf = new ExcelDataSetConfiguration
            {
                ConfigureDataTable = _ => new ExcelDataTableConfiguration
                {
                    UseHeaderRow = true
                }
            };
            dataSet = reader.AsDataSet(conf);
            cboSheet.Items.Clear();
            foreach (DataTable dt in dataSet.Tables)
                cboSheet.Items.Add(dt.TableName);
            reader.Close();
        }
    }
}

private void cboSheet_SelectedIndexChanged(object sender, EventArgs e)
{
    dataGridView.DataSource = dataSet.Tables[cboSheet.SelectedIndex];
}

Answer 1

Do you know the excel file will be the same each time? If you can ensure the file will be consistently the same without any column modifications, you can do the following with OfficeOpenXml package.

public IEnumerable<string> ReadFile(string path)
{
     using(var file = new FileStream(path, FileMode.Open))
     using(var memory = new MemoryStream())
     {
          file.CopyTo(memory);
          using(var package = new ExcelPackage(memory))
               if(package.Workbook.Worksheets.Count != 0)
                    foreach(ExcelWorksheet worksheet in package.Workbook.Worksheets)
                         for(var row = 0; worksheet.Dimension.Start.Row; row <= worksheet.Dimension.End.Row; row++)
                              yield return worksheet.Cells[row, 2].Value;
     }
}

For brevity I didn't abstract, you could make the code a bit more clear by separating the multiple loop, for worksheet then the rows. As you can see the "2" is representing the specified column. But that would give you a collection you could iterate to dump into your query to process.

Answer 2

You can use ExcelDataReader , that will give you the entire excel content as DataTable

Or you can use OleDbCommand

    OleDbConnection conn = new OleDbConnection("Provider=Microsoft.ACE.OLEDB.12.0;Data Source=" + ExcelPath + "; Extended Properties = 'Excel 12.0;HDR=YES;';");

    conn.Open();

    OleDbCommand cmd = new OleDbCommand();

    cmd.Connection = conn;

    cmd.CommandText = SELECT [Colum1], [Colum2] FROM [Sheet1$];

    OleDbDataReader reader =  cmd.ExecuteReader();