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How to access csv file and insert data into csv

I am trying to insert data into csv file. I tried using XLWorkbook reference to access and insert data but I know that XLWorkbook can only support extension which are xlsx,xslm,xltx and xltm.
I am trying to find something similar to what I am trying to achieve through which I can insert data into specified column in csv file. I have used XLWorkbook for some other purpose but I am not aware to what I can use when I have to use csv.
//Accessing the csv file where I am trying to insert data.
string rootPath = Path.GetDirectoryName(Assembly.GetExecutingAssembly().CodeBase);
string filelocation = #"\csv\TestData.csv";
string location = rootPath + filelocation;
XLWorkbook workbook = new XLWorkbook(pathfile);
IXLWorksheet worksheet = workbook.Worksheet("Sheet1");
//Insert data after first row as first row contains column header
int lastrow = worksheet.LastRowUsed().RowNumber() + 1;
//through previous function I am trying get data from database and insert those data into csv cells
worksheet.Cell(String.Format("B{0}", lastrow)).Value = dummydata.FirstName;
worksheet.Cell(String.Format("C{0}", lastrow)).Value = dummydata.LastName;
worksheet.Cell(String.Format("D{0}", lastrow)).Value = dummydata.Address1;
worksheet.Cell(String.Format("E{0}", lastrow)).Value = dummydata.Address2;
worksheet.Cell(String.Format("F{0}", lastrow)).Value = dummydata.City;
worksheet.Cell(String.Format("G{0}", lastrow)).Value = dummydata.StateProvinceCode;
worksheet.Cell(String.Format("H{0}", lastrow)).Value = dummydata.ZipCode;
worksheet.Cell(String.Format("I{0}", lastrow)).Value = dummydata.Country;
worksheet.Cell(String.Format("J{0}", lastrow)).Value = dummydata.HomePhone;
worksheet.Cell(String.Format("L{0}", lastrow)).Value = dummydata.HomePhone;
worksheet.Cell(String.Format("M{0}", lastrow)).Value = dummydata.CellPhone;
worksheet.Cell(String.Format("T{0}", lastrow)).Value = dummydata.Email;
worksheet.Cell(String.Format("U{0}", lastrow)).Value = dummydata.Country;
//After inserting save the file
workbook.Save();

You can simply copy and use this code as is. It should resolve your issues.
Here's the class I developed to replace and/or add csv cells:
using System.Collections.Generic;
using System.IO;
using System.Linq;
using System.Text;
namespace CSVManager
{
public class CSVWorker
{
private string m_FileName = string.Empty;
public CSVWorker(string fileName)
{
m_FileName = fileName;
}
public void AddCells(int row, int column, string newValue)
{
var encoding = Encoding.GetEncoding("iso-8859-1");
var csvLines = File.ReadAllLines(m_FileName, encoding);
if (row < csvLines.Length)
{
ReplaceCells(row, column, newValue);
}
else
{
using (FileStream stream = new FileStream(m_FileName, FileMode.Create))
{
using (StreamWriter writer = new StreamWriter(stream, encoding))
{
foreach (var line in csvLines)
{
writer.WriteLine(line);
}
int blankLines = row - csvLines.Length - 1;
for (int i = 0; i < blankLines; i++)
{
writer.WriteLine("");
}
string blankCols = string.Empty;
for (int i = 0; i < column-1; i++)
{
blankCols += ',';
}
writer.WriteLine(blankCols + newValue);
}
}
}
}
public void ReplaceCells(int row, int column, string newValue)
{
var encoding = Encoding.GetEncoding("iso-8859-1");
var csvLines = File.ReadAllLines(m_FileName, encoding);
for (int i = 0; i < csvLines.Length; i++)
{
//var values = csvLines[i].Split(',');
List <string> values = csvLines[i].Split(',').ToList();
if (i == row)
{
if (column < values.Count)
{
values[column] = newValue;
}
else
{
while (values.Count < column - 1)
{
values.Append(",");
}
values.Append(newValue);
}
using (FileStream stream = new FileStream(m_FileName, FileMode.Create))
{
using (StreamWriter writer = new StreamWriter(stream, encoding))
{
for (int currentLine = 0; currentLine < csvLines.Length; ++currentLine)
{
if (currentLine == i)
{
writer.WriteLine(string.Join(",", values));
}
else
{
writer.WriteLine(csvLines[currentLine]);
}
}
writer.Close();
}
stream.Close();
break;
}
}
}
}
}
}
Here's how I used it:
namespace CSVManager
{
class Program
{
static void Main(string[] args)
{
string fileName = #"C:\Users\mklig\Documents\TestCsv.csv";
CSVWorker csvWorker = new CSVWorker(fileName);
int row = 4;
int col = 4;
string newVal = "success";
//csvWorker.ReplaceCells(row, col, newVal);
csvWorker.AddCells(row, col, newVal);
}
}
}

.Net Core: Reading data from CSV & Excel files

Using .net core & c# here.
I have a UI from which user can upload the Excel or CSV files. Once they upload this goes to my web api which handles the reading of the data from these files and returns json.
My Api code as:
[HttpPost("upload")]
public async Task<IActionResult> FileUpload(IFormFile file)
{
JArray data = new JArray();
using (ExcelPackage package = new ExcelPackage(file.OpenReadStream()))
{
ExcelWorksheet worksheet = package.Workbook.Worksheets[1];
//Process, read from excel here and populate jarray
}
return Ok(data );
}
In my above code I am using EPPlus for reading the excel file. For excel file it works all fine but it cannot read csv file which is the limitation of EPPlus.
I searched and found another library CSVHelper: https://joshclose.github.io/CsvHelper/ The issue with this is it does vice versa and can read from CSV but not from Excel.
Is there any library available which supports reading from both.
Or would it be possible use EPPlus only but convert uploaded CSV to excel on the fly and then read. (please note I am not storing the excel file anywhere so cant use save as to save it as excel)
Any inputs please?
--Updated - Added code for reading data from excel---
int rowCount = worksheet.Dimension.End.Row;
int colCount = worksheet.Dimension.End.Column;
for (int row = 1; row <= rowCount; row++)
{
for (int col = 1; col <= colCount; col++)
{
var rowValue = worksheet.Cells[row, col].Value;
}
}
//With the code suggested in the answer rowcount is always 1

You can use EPPLus and a MemoryStream for opening csv files into an ExcelPackage without writing to a file. Below is an example. You may have to change some of the the parameters based on your CSV file specs.
[HttpPost("upload")]
public async Task<IActionResult> FileUpload(IFormFile file)
{
var result = string.Empty;
string worksheetsName = "data";
bool firstRowIsHeader = false;
var format = new ExcelTextFormat();
format.Delimiter = ',';
format.TextQualifier = '"';
using (var reader = new System.IO.StreamReader(file.OpenReadStream()))
using (ExcelPackage package = new ExcelPackage())
{
result = reader.ReadToEnd();
ExcelWorksheet worksheet =
package.Workbook.Worksheets.Add(worksheetsName);
worksheet.Cells["A1"].LoadFromText(result, format, OfficeOpenXml.Table.TableStyles.Medium27, firstRowIsHeader);
}
}

Here's using Aspose, which is unfortunately not free, but wow it works great. My API is using the streaming capability with Content-Type: multipart/form-data rather than the IFormFile implementation:
[HttpPut]
[DisableFormValueModelBinding]
public async Task<IActionResult> UploadSpreadsheet()
{
if (!MultipartRequestHelper.IsMultipartContentType(Request.ContentType))
{
return BadRequest($"Expected a multipart request, but got {Request.ContentType}");
}
var boundary = MultipartRequestHelper.GetBoundary(MediaTypeHeaderValue.Parse(Request.ContentType), _defaultFormOptions.MultipartBoundaryLengthLimit);
var reader = new MultipartReader(boundary, HttpContext.Request.Body);
var section = (await reader.ReadNextSectionAsync()).AsFileSection();
//If you're doing CSV, you add this line:
LoadOptions loadOptions = new LoadOptions(LoadFormat.CSV);
var workbook = new Workbook(section.FileStream, loadOptions);
Cells cells = workbook.Worksheets[0].Cells;
var rows = cells.Rows.Cast<Row>().Where(x => !x.IsBlank);
//Do whatever else you want here

Please try with below code
private string uploadCSV(FileUpload fl)
{
string fileName = "";
serverLocation = Request.PhysicalApplicationPath + "ExcelFiles\\";
fileName = fl.PostedFile.FileName;
int FileSize = fl.PostedFile.ContentLength;
string contentType = fl.PostedFile.ContentType;
fl.PostedFile.SaveAs(serverLocation + fileName);
string rpath = string.Empty, dir = string.Empty;
HttpContext context = HttpContext.Current;
string baseUrl = context.Request.Url.Scheme + "://" + context.Request.Url.Authority + context.Request.ApplicationPath.TrimEnd('/') + '/';
try
{
rpath = serverLocation + fileName;//Server.MapPath(dir + fileName);
using (Stream InputStream = fl.PostedFile.InputStream)
{
Object o = new object();
lock (o)
{
byte[] buffer = new byte[InputStream.Length];
InputStream.Read(buffer, 0, (int)InputStream.Length);
lock (o)
{
File.WriteAllBytes(rpath, buffer);
buffer = null;
}
InputStream.Close();
}
}
}
catch (Exception ex)
{
lblSOTargetVal.Text = ex.Message.ToString();
}
return rpath;
}

Use the Open XML SDK package and add insert working solution for it.

Return File in net Core is corrupted when using FileStreamResult

I have a method that returns a FileStreamResult to download a file created by NPOI, an Excel file. In the method i use a sample to save locally the file in wwwroot with FileStream and it works, but when i need to return the file and download in front end, the file downloaded is corrupted.
The file is open, and contains the columns that i write.
The file created locally is open normally.
This is the method:
public IActionResult DescargarRepEstacion()
{
if (!ModelState.IsValid) {
return StatusCode(400, ModelState);
}
try
{
var fullPath = Path.Combine(_hostingEnvironment.WebRootPath, "Formatos", "Formato Estacion.xls");
var workBook = new HSSFWorkbook();
var sheet = workBook.CreateSheet("Formato Estación");
var rowIndex = 0;
var row = sheet.CreateRow(rowIndex);
row.CreateCell(0).SetCellValue("ID");
row.CreateCell(1).SetCellValue("DESTINO");
row.CreateCell(2).SetCellValue("PERMISO");
row.CreateCell(3).SetCellValue("TERMINAL");
rowIndex++;
var ms = new MemoryStream();
workBook.Write(ms);
using (var file = new FileStream(fullPath, FileMode.Create)) {
workBook.Write(file);
}
ms.Position = 0;
return new FileStreamResult(ms, "application/vnd.ms-excel");
}
catch (Exception ex) {
return StatusCode(500, ex.Message.ToString());
}
}
In the front end:
axios.get("Formatos/DescargarEstacion", {
headers: {
Authorization: "Bearer " + localStorage.getItem("token"),
'Content-Type': 'application/json',
'Accept':'application/vnd.ms-excel',
}
}).then(response => {
this.loadingDownloadEstacion = false;
download(response.data, 'Formato Estacion.xls');
console.log(response.data);
// const url = window.URL.createObjectURL(new Blob([response.data]));
// const link = document.createElement('a');
// link.href = url;
// link.setAttribute('download', 'Formato Estaciones.xls');
// document.body.appendChild(link);
// link.click();
}).catch(error => {
this.loadingDownloadEstacion = false;
console.log(error.response);
this.snackbar = true;
this.textSnackbar = error.response.data;
})
What am i doing wrong?
UPDATE WHIT SCREENSHOT:

Efficiently Convert .xslx to .csv in C#?

As input, I have a set of excel files with several worksheets inside. I need to export a single csv file for each worksheet. Below is my code which works but it is very slow. It builds upon the solutions proposed in this previous post. Please consider that I have to run this on rather big .xlsx files (approx. 300Mb).
QUESTION: Is there any way to improve this?
void Main()
{
string folder = #"\\PATH_TO_FOLDER\";
var files = Directory.GetFiles(folder, "*.xlsx", SearchOption.TopDirectoryOnly);
foreach (string file in files)
{
ConvertToCsv(file, Directory.GetParent(file) + #"\\output\");
}
}
public static void ConvertToCsv(string file, string targetFolder)
{
FileInfo finfo = new FileInfo(file);
ExcelPackage package = new ExcelPackage(finfo);
// if targetFolder doesn't exist, create it
if (!Directory.Exists(targetFolder)) {
Directory.CreateDirectory(targetFolder);
}
var worksheets = package.Workbook.Worksheets;
int sheetcount = 0;
foreach (ExcelWorksheet worksheet in worksheets)
{
sheetcount++;
var maxColumnNumber = worksheet.Dimension.End.Column;
var currentRow = new List<string>(maxColumnNumber);
var totalRowCount = worksheet.Dimension.End.Row+1;
var currentRowNum = 1;
//No need for a memory buffer, writing directly to a file
//var memory = new MemoryStream();
string file_name = targetFolder + Path.GetFileNameWithoutExtension(file) + "_" + sheetcount + ".csv";
using (var writer = new StreamWriter(file_name, false, Encoding.UTF8))
{
//the rest of the code remains the same
for (int i = 1; i < totalRowCount; i++)
{
i.Dump();
// populate line with semi columns separators
string line = "";
for (int j = 1; j < worksheet.Dimension.End.Column+1; j++)
{
if (worksheet.Cells[i, j].Value != null)
{
string cell = worksheet.Cells[i, j].Value.ToString() + ";";
line += cell;
}
}
// write line
writer.WriteLine(line);
}
}
}
}

Html table convert as excel and send via email

I'm developing an app which can generate a excel file using html table. Up to now I developed html table download as excel file part. (This happens in client side with javascript). Now I need to send email with that attachment (The excel file) to particular person's email address. So I'm confuse how to do this, because up to now I generate excel in client side and need to send that file via email. In this case is it needed to copy client side excel to the server? If so how to do this?
Please give me a direction.
Update 1 (Adding codes)
This is the javascript, that I used to download html table as excel to client side.
var tablesToExcel = (function () {
var uri = 'data:application/vnd.ms-excel;base64,'
, tmplWorkbookXML = '<?xml version="1.0"?><?mso-application progid="Excel.Sheet"?><Workbook xmlns="urn:schemas-microsoft-com:office:spreadsheet" xmlns:ss="urn:schemas-microsoft-com:office:spreadsheet">'
+ '<DocumentProperties xmlns="urn:schemas-microsoft-com:office:office"><Author>Axel Richter</Author><Created>{created}</Created></DocumentProperties>'
+ '<Styles>'
+ '<Style ss:ID="Currency"><NumberFormat ss:Format="Currency"></NumberFormat></Style>'
+ '<Style ss:ID="Date"><NumberFormat ss:Format="Medium Date"></NumberFormat></Style>'
+ '</Styles>'
+ '{worksheets}</Workbook>'
, tmplWorksheetXML = '<Worksheet ss:Name="{nameWS}"><Table>{rows}</Table></Worksheet>'
, tmplCellXML = '<Cell{attributeStyleID}{attributeFormula}><Data ss:Type="{nameType}">{data}</Data></Cell>'
, base64 = function (s) { return window.btoa(unescape(encodeURIComponent(s))) }
, format = function (s, c) { return s.replace(/{(\w+)}/g, function (m, p) { return c[p]; }) }
return function (tables, wsnames, wbname, appname) {
var ctx = "";
var workbookXML = "";
var worksheetsXML = "";
var rowsXML = "";
for (var i = 0; i < tables.length; i++) {
if (!tables[i].nodeType) tables[i] = document.getElementById(tables[i]);
for (var j = 0; j < tables[i].rows.length; j++) {
rowsXML += '<Row>'
for (var k = 0; k < tables[i].rows[j].cells.length; k++) {
var dataType = tables[i].rows[j].cells[k].getAttribute("data-type");
var dataStyle = tables[i].rows[j].cells[k].getAttribute("data-style");
var dataValue = tables[i].rows[j].cells[k].getAttribute("data-value");
dataValue = (dataValue) ? dataValue : tables[i].rows[j].cells[k].innerHTML;
var dataFormula = tables[i].rows[j].cells[k].getAttribute("data-formula");
dataFormula = (dataFormula) ? dataFormula : (appname == 'Calc' && dataType == 'DateTime') ? dataValue : null;
ctx = {
attributeStyleID: (dataStyle == 'Currency' || dataStyle == 'Date') ? ' ss:StyleID="' + dataStyle + '"' : ''
, nameType: (dataType == 'Number' || dataType == 'DateTime' || dataType == 'Boolean' || dataType == 'Error') ? dataType : 'String'
, data: (dataFormula) ? '' : dataValue
, attributeFormula: (dataFormula) ? ' ss:Formula="' + dataFormula + '"' : ''
};
rowsXML += format(tmplCellXML, ctx);
}
rowsXML += '</Row>'
}
ctx = { rows: rowsXML, nameWS: wsnames[i] || 'Sheet' + i };
worksheetsXML += format(tmplWorksheetXML, ctx);
rowsXML = "";
}
ctx = { created: (new Date()).getTime(), worksheets: worksheetsXML };
workbookXML = format(tmplWorkbookXML, ctx);
var link = document.createElement("A");
link.href = uri + base64(workbookXML);
link.download = wbname || 'Workbook.xls';
link.target = '_blank';
document.body.appendChild(link);
link.click();
document.body.removeChild(link);
}
})();
Still I do not have idea to save generated excel to server and send it as email.

AS per our discussion:
1. you need to send data from client to server
you can use this code to do this sending headers and values to server using ajax and you can also filter columns as you want
function SaveToServer() {
var gov = GetHeaders('tbl');
$.ajax({
url: '#Url.Content("~/Home/ReciveData")',
data: { headers: JSON.stringify(gov.heasers), data: JSON.stringify(gov.data) },
success: function (data) {
// Success
},
error: function (xhr) {
}
});
}
function GetHeaders(tableName) {
table = document.getElementById(tableName);
var tbl_Hdata = [];
var tbl_Data = [];
for (var i = 0, row; row = table.rows[i]; i++) {
var rowData = [];
for (var j = 0, col; col = row.cells[j]; j++) {
// add column filter
if (i == 0) {
tbl_Hdata.push(col.innerHTML);
}
else {
rowData.push(col.innerHTML);
}
}
if (i > 0) {
tbl_Data.push(rowData);
}
}
return { heasers: tbl_Hdata, data: tbl_Data };
}
now we want to recive this data and convert it to datatable to save it to excel in server side
using NPOI
public void ReciveData(string headers, string data)
{
#region Read Data
List<string> tbl_Headers = new List<string>();
List<List<string>> tbl_Data = new List<List<string>>();
tbl_Headers = Newtonsoft.Json.JsonConvert.DeserializeObject<List<string>>(headers);
tbl_Data = Newtonsoft.Json.JsonConvert.DeserializeObject<List<List<string>>>(data);
#endregion
#region Create Data Table
DataTable dataTable = new DataTable("Data");
foreach (var prop in tbl_Headers)
{
dataTable.Columns.Add(prop);
}
DataRow row;
foreach (var rw in tbl_Data)
{
row = dataTable.NewRow();
for (int i = 0; i < rw.Count; i++)
{
row[tbl_Headers[i]] = rw[i];
}
dataTable.Rows.Add(row);
}
#endregion
#region Save To excel
string path = #"D:\";
string fileName = "";
GenerateExcelSheetWithoutDownload(dataTable, path, out fileName);
#endregion
}
public bool GenerateExcelSheetWithoutDownload(DataTable dataTable, string exportingSheetPath, out string exportingFileName)
{
#region Validate the parameters and Generate the excel sheet
bool returnValue = false;
exportingFileName = Guid.NewGuid().ToString() + ".xls";
if (dataTable != null && dataTable.Rows.Count > new int())
{
string excelSheetPath = string.Empty;
#region Check If The directory is exist
if (!Directory.Exists(exportingSheetPath))
{
Directory.CreateDirectory(exportingSheetPath);
}
excelSheetPath = exportingSheetPath + exportingFileName;
FileInfo fileInfo = new FileInfo(excelSheetPath);
#endregion
#region Write stream to the file
MemoryStream ms = DataToExcel(dataTable);
byte[] blob = ms.ToArray();
if (blob != null)
{
using (MemoryStream inStream = new MemoryStream(blob))
{
FileStream fs = new FileStream(excelSheetPath, FileMode.Create);
inStream.WriteTo(fs);
fs.Close();
}
}
ms.Close();
returnValue = true;
#endregion
}
return returnValue;
#endregion
}
private static MemoryStream DataToExcel(DataTable dt)
{
MemoryStream ms = new MemoryStream();
using (dt)
{
#region Create File
HSSFWorkbook workbook = new HSSFWorkbook();//Create an excel Workbook
ISheet sheet = workbook.CreateSheet("data");//Create a work table in the table
int RowHeaderIndex = new int();
#endregion
#region Table Headers
IRow headerTableRow = sheet.CreateRow(RowHeaderIndex);
if (dt != null)
{
foreach (DataColumn column in dt.Columns)
{
headerTableRow.CreateCell(column.Ordinal).SetCellValue(column.Caption);
}
RowHeaderIndex++;
}
#endregion
#region Data
foreach (DataRow row in dt.Rows)
{
IRow dataRow = sheet.CreateRow(RowHeaderIndex);
foreach (DataColumn column in dt.Columns)
{
dataRow.CreateCell(column.Ordinal).SetCellValue(row[column].ToString());
}
RowHeaderIndex++;
}
#endregion
workbook.Write(ms);
ms.Flush();
//ms.Position = 0;
}
return ms;
}
Now you can send this file as attachment in mail

You can't create Excel files with HTML tables. This is a hack that's used to fake actual Excel files. Excel isn't fooled, it recognizes the HTML file and tries to import the data using defaults. This will easily break for any number of reasons, eg different locale settings for decimals and dates.
Excel files are just zipped XML files. You can create them using XML manipulation, the Open XML SDK or a library like EPPlus.
Creating an Excel file with EPPlus is as easy as calling the LoadFromCollection or LoadFromDatatable method. The sheet can be saved to any stream, including FileStream or MemoryStream. A MemoryStream can be used to send the data to a web browser as shown in this answer:
public ActionResult ExportData()
{
//Somehow, load data to a DataTable
using (ExcelPackage package = new ExcelPackage())
{
var ws = package.Workbook.Worksheets.Add("My Sheet");
//true generates headers
ws.Cells["A1"].LoadFromDataTable(dataTable, true);
var stream = new MemoryStream();
package.SaveAs(stream);
string fileName = "myfilename.xlsx";
string contentType = "application/vnd.openxmlformats-officedocument.spreadsheetml.sheet";
stream.Position = 0;
return File(stream, contentType, fileName);
}
}
Mail attachments can also be created from a MemoryStream. The Attachment(Stream, string,string) constructor accepts any stream as input. The example above could be modified to create an attachment instead of sending the data to the browser:
public void SendData(string server, string recipientList)
{
//Same as before
using (ExcelPackage package = new ExcelPackage())
{
var ws = package.Workbook.Worksheets.Add("My Sheet");
ws.Cells["A1"].LoadFromDataTable(dataTable, true);
var stream = new MemoryStream();
package.SaveAs(stream);
string fileName = "myfilename.xlsx";
string contentType = "application/vnd.openxmlformats-officedocument.spreadsheetml.sheet";
stream.Position = 0;
SendExcel(server,recipientList);
}
}
void SendExcel(string server, string recipientList)
{
//Send the file
var message = new MailMessage("logMailer#contoso.com", recipientList);
message.Subject = "Some Data";
Attachment data = new Attachment(stream, name, contentType);
// Add the attachment to the message.
message.Attachments.Add(data);
// Send the message.
// Include credentials if the server requires them.
var client = new SmtpClient(server);
client.Credentials = CredentialCache.DefaultNetworkCredentials;
client.Send(message);
}
}
UPDATE
Generating an XSLX table on the client side becomes a lot easier if you use a library like js-xlsx. There's even a sample that generates an XLSX file from an HTML table