[c#] How do I import from Excel to a DataSet using Microsoft.Office.Interop.Excel?

What I want to do

I'm trying to use the Microsoft.Office.Interop.Excel namespace to open an Excel file (XSL or CSV, but sadly not XSLX) and import it into a DataSet. I don't have control over the worksheet or column names, so I need to allow for changes to them.

What I've tried

I've tried the OLEDB method of this in the past, and had a lot of problems with it (buggy, slow, and required prior knowledge of the Excel file's schema), so I want to avoid doing that again. What I'd like to do is use Microsoft.Office.Interop.Excel to import the workbook directly to a DataSet, or loop through the worksheets and load each one into a DataTable.

Believe it or not, I've had trouble finding resources for this. A few searches on StackOverflow have found mostly people trying to do the reverse (DataSet => Excel), or the OLEDB technique. Google hasn't been much more helpful.

What I've got so far

    public void Load(string filename, Excel.XlFileFormat format = Excel.XlFileFormat.xlCSV)
    {
        app = new Excel.Application();
        book = app.Workbooks.Open(Filename: filename, Format: format);

        DataSet ds = new DataSet();

        foreach (Excel.Worksheet sheet in book.Sheets)
        {
            DataTable dt = new DataTable(sheet.Name);
            ds.Tables.Add(dt);

            //??? Fill dt from sheet 
        }

        this.Data = ds;
    }

I'm fine with either importing the entire book at once, or looping through one sheet at a time. Can I do this with Interop.Excel?

This question is related to c# excel interop dataset excel-interop

The answer is


Quiet Late though!.

This method is properly tested and it converts the excel to DataSet.

public DataSet Dtl()
        {
            //Instance reference for Excel Application
            Microsoft.Office.Interop.Excel.Application objXL = null;        
            //Workbook refrence
            Microsoft.Office.Interop.Excel.Workbook objWB = null;
            DataSet ds = new DataSet();
            try
            {
                objXL = new Microsoft.Office.Interop.Excel.Application();
                objWB = objXL.Workbooks.Open(@"Book1.xlsx");//Your path to excel file.
                foreach (Microsoft.Office.Interop.Excel.Worksheet objSHT in objWB.Worksheets)
                {
                    int rows = objSHT.UsedRange.Rows.Count;
                    int cols = objSHT.UsedRange.Columns.Count;
                    DataTable dt = new DataTable();
                    int noofrow = 1;
                    //If 1st Row Contains unique Headers for datatable include this part else remove it
                    //Start
                    for (int c = 1; c <= cols; c++)
                    {
                        string colname = objSHT.Cells[1, c].Text;
                        dt.Columns.Add(colname);
                        noofrow = 2;
                    }
                    //END
                    for (int r = noofrow; r <= rows; r++)
                    {
                        DataRow dr = dt.NewRow();
                        for (int c = 1; c <= cols; c++)
                        {
                            dr[c - 1] = objSHT.Cells[r, c].Text;
                        }
                        dt.Rows.Add(dr);
                    }
                   ds.Tables.Add(dt);
                }
                //Closing workbook
                objWB.Close();
                //Closing excel application
                objXL.Quit();
                return ds;
            }

            catch (Exception ex)
            {
               objWB.Saved = true;
                //Closing work book
                objWB.Close();
                //Closing excel application
                objXL.Quit();
                //Response.Write("Illegal permission");
                return ds;
            }
        }

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Data;
using System.Reflection;
using Microsoft.Office.Interop.Excel;

namespace trg.satmap.portal.ParseAgentSkillMapping
{
    class ConvertXLStoDT
    {
        private StringBuilder errorMessages;

        public StringBuilder ErrorMessages
        {
            get { return errorMessages; }
            set { errorMessages = value; }
        }

        public ConvertXLStoDT()
        {
            ErrorMessages = new StringBuilder();
        }

        public System.Data.DataTable XLStoDTusingInterOp(string FilePath)
        {
            #region Excel important Note.
            /*
             * Excel creates XLS and XLSX files. These files are hard to read in C# programs. 
             * They are handled with the Microsoft.Office.Interop.Excel assembly. 
             * This assembly sometimes creates performance issues. Step-by-step instructions are helpful.
             * 
             * Add the Microsoft.Office.Interop.Excel assembly by going to Project -> Add Reference.
             */
            #endregion

            Microsoft.Office.Interop.Excel.Application excelApp = null;
            Microsoft.Office.Interop.Excel.Workbook workbook = null;


            System.Data.DataTable dt = new System.Data.DataTable(); //Creating datatable to read the content of the Sheet in File.

            try
            {

                excelApp = new Microsoft.Office.Interop.Excel.Application(); // Initialize a new Excel reader. Must be integrated with an Excel interface object.

                //Opening Excel file(myData.xlsx)
                workbook = excelApp.Workbooks.Open(FilePath, Missing.Value, Missing.Value, Missing.Value, Missing.Value, Missing.Value, Missing.Value, Missing.Value, Missing.Value, Missing.Value, Missing.Value, Missing.Value, Missing.Value, Missing.Value, Missing.Value);

                Microsoft.Office.Interop.Excel.Worksheet ws = (Microsoft.Office.Interop.Excel.Worksheet)workbook.Sheets.get_Item(1);

                Microsoft.Office.Interop.Excel.Range excelRange = ws.UsedRange; //gives the used cells in sheet

                ws = null; // now No need of this so should expire.

                //Reading Excel file.               
                object[,] valueArray = (object[,])excelRange.get_Value(Microsoft.Office.Interop.Excel.XlRangeValueDataType.xlRangeValueDefault);

                excelRange = null; // you don't need to do any more Interop. Now No need of this so should expire.

                dt = ProcessObjects(valueArray);                

            }
            catch (Exception ex)
            {
                ErrorMessages.Append(ex.Message);
            }
            finally
            {
                #region Clean Up                
                if (workbook != null)
                {
                    #region Clean Up Close the workbook and release all the memory.
                    workbook.Close(false, FilePath, Missing.Value);                    
                    System.Runtime.InteropServices.Marshal.ReleaseComObject(workbook);
                    #endregion
                }
                workbook = null;

                if (excelApp != null)
                {
                    excelApp.Quit();
                }
                excelApp = null;                

                #endregion
            }
            return (dt);
        }

        /// <summary>
        /// Scan the selected Excel workbook and store the information in the cells
        /// for this workbook in an object[,] array. Then, call another method
        /// to process the data.
        /// </summary>
        private void ExcelScanIntenal(Microsoft.Office.Interop.Excel.Workbook workBookIn)
        {
            //
            // Get sheet Count and store the number of sheets.
            //
            int numSheets = workBookIn.Sheets.Count;

            //
            // Iterate through the sheets. They are indexed starting at 1.
            //
            for (int sheetNum = 1; sheetNum < numSheets + 1; sheetNum++)
            {
                Worksheet sheet = (Worksheet)workBookIn.Sheets[sheetNum];

                //
                // Take the used range of the sheet. Finally, get an object array of all
                // of the cells in the sheet (their values). You can do things with those
                // values. See notes about compatibility.
                //
                Range excelRange = sheet.UsedRange;
                object[,] valueArray = (object[,])excelRange.get_Value(XlRangeValueDataType.xlRangeValueDefault);

                //
                // Do something with the data in the array with a custom method.
                //
                ProcessObjects(valueArray);
            }
        }
        private System.Data.DataTable ProcessObjects(object[,] valueArray)
        {
            System.Data.DataTable dt = new System.Data.DataTable();

            #region Get the COLUMN names

            for (int k = 1; k <= valueArray.GetLength(1); k++)
            {
                dt.Columns.Add((string)valueArray[1, k]);  //add columns to the data table.
            }
            #endregion

            #region Load Excel SHEET DATA into data table

            object[] singleDValue = new object[valueArray.GetLength(1)];
            //value array first row contains column names. so loop starts from 2 instead of 1
            for (int i = 2; i <= valueArray.GetLength(0); i++)
            {
                for (int j = 0; j < valueArray.GetLength(1); j++)
                {
                    if (valueArray[i, j + 1] != null)
                    {
                        singleDValue[j] = valueArray[i, j + 1].ToString();
                    }
                    else
                    {
                        singleDValue[j] = valueArray[i, j + 1];
                    }
                }
                dt.LoadDataRow(singleDValue, System.Data.LoadOption.PreserveChanges);
            }
            #endregion


            return (dt);
        }
    }
}

Years after everyone's answer, I too want to present how I did it for my project

    /// <summary>
    /// /Reads an excel file and converts it into dataset with each sheet as each table of the dataset
    /// </summary>
    /// <param name="filename"></param>
    /// <param name="headers">If set to true the first row will be considered as headers</param>
    /// <returns></returns>
    public DataSet Import(string filename, bool headers = true)
    {
        var _xl = new Excel.Application();
        var wb = _xl.Workbooks.Open(filename);
        var sheets = wb.Sheets;
        DataSet dataSet = null;
        if (sheets != null && sheets.Count != 0)
        {
            dataSet = new DataSet();
            foreach (var item in sheets)
            {
                var sheet = (Excel.Worksheet)item;
                DataTable dt = null;
                if (sheet != null)
                {
                    dt = new DataTable();
                    var ColumnCount = ((Excel.Range)sheet.UsedRange.Rows[1, Type.Missing]).Columns.Count;
                    var rowCount = ((Excel.Range)sheet.UsedRange.Columns[1, Type.Missing]).Rows.Count;

                    for (int j = 0; j < ColumnCount; j++)
                    {
                        var cell = (Excel.Range)sheet.Cells[1, j + 1];
                        var column = new DataColumn(headers ? cell.Value : string.Empty);
                        dt.Columns.Add(column);
                    }

                    for (int i = 0; i < rowCount; i++)
                    {
                        var r = dt.NewRow();
                        for (int j = 0; j < ColumnCount; j++)
                        {
                            var cell = (Excel.Range)sheet.Cells[i + 1 + (headers ? 1 : 0), j + 1];
                            r[j] = cell.Value;
                        }
                        dt.Rows.Add(r);
                    }

                }
                dataSet.Tables.Add(dt);
            }
        }
        _xl.Quit();
        return dataSet;
    }

object[,] valueArray = (object[,])excelRange.get_Value(XlRangeValueDataType.xlRangeValueDefault);

//Get the column names
for (int k = 0; k < valueArray.GetLength(1); )
{
    //add columns to the data table.
    dt.Columns.Add((string)valueArray[1,++k]);
}

//Load data into data table
object[] singleDValue = new object[valueArray.GetLength(1)];
//value array first row contains column names. so loop starts from 1 instead of 0
for (int i = 1; i < valueArray.GetLength(0); i++)
{
    Console.WriteLine(valueArray.GetLength(0) + ":" + valueArray.GetLength(1));
    for (int k = 0; k < valueArray.GetLength(1); )
    {
        singleDValue[k] = valueArray[i+1, ++k];
    }
    dt.LoadDataRow(singleDValue, System.Data.LoadOption.PreserveChanges);
}

Have you seen this one? From http://www.aspspider.com/resources/Resource510.aspx:

public DataTable Import(String path)
{
    Microsoft.Office.Interop.Excel.Application app = new Microsoft.Office.Interop.Excel.Application();
    Microsoft.Office.Interop.Excel.Workbook workBook = app.Workbooks.Open(path, 0, true, 5, "", "", true, Microsoft.Office.Interop.Excel.XlPlatform.xlWindows, "\t", false, false, 0, true, 1, 0);

    Microsoft.Office.Interop.Excel.Worksheet workSheet = (Microsoft.Office.Interop.Excel.Worksheet)workBook.ActiveSheet;

    int index = 0;
    object rowIndex = 2;

    DataTable dt = new DataTable();
    dt.Columns.Add("FirstName");
    dt.Columns.Add("LastName");
    dt.Columns.Add("Mobile");
    dt.Columns.Add("Landline");
    dt.Columns.Add("Email");
    dt.Columns.Add("ID");

    DataRow row;

    while (((Microsoft.Office.Interop.Excel.Range)workSheet.Cells[rowIndex, 1]).Value2 != null)
    {

        row = dt.NewRow();
        row[0] = Convert.ToString(((Microsoft.Office.Interop.Excel.Range)workSheet.Cells[rowIndex, 1]).Value2);
        row[1] = Convert.ToString(((Microsoft.Office.Interop.Excel.Range)workSheet.Cells[rowIndex, 2]).Value2);
        row[2] = Convert.ToString(((Microsoft.Office.Interop.Excel.Range)workSheet.Cells[rowIndex, 3]).Value2);
        row[3] = Convert.ToString(((Microsoft.Office.Interop.Excel.Range)workSheet.Cells[rowIndex, 4]).Value2);
        row[4] = Convert.ToString(((Microsoft.Office.Interop.Excel.Range)workSheet.Cells[rowIndex, 5]).Value2);
        index++;

        rowIndex = 2 + index;
        dt.Rows.Add(row);
    }
    app.Workbooks.Close();
    return dt;
}

Examples related to c#

How can I convert this one line of ActionScript to C#? Microsoft Advertising SDK doesn't deliverer ads How to use a global array in C#? How to correctly write async method? C# - insert values from file into two arrays Uploading into folder in FTP? Are these methods thread safe? dotnet ef not found in .NET Core 3 HTTP Error 500.30 - ANCM In-Process Start Failure Best way to "push" into C# array

Examples related to excel

Python: Pandas pd.read_excel giving ImportError: Install xlrd >= 0.9.0 for Excel support Converting unix time into date-time via excel How to increment a letter N times per iteration and store in an array? 'Microsoft.ACE.OLEDB.16.0' provider is not registered on the local machine. (System.Data) How to import an Excel file into SQL Server? Copy filtered data to another sheet using VBA Better way to find last used row Could pandas use column as index? Check if a value is in an array or not with Excel VBA How to sort dates from Oldest to Newest in Excel?

Examples related to interop

Exception from HRESULT: 0x800A03EC Error How to use Microsoft.Office.Interop.Excel on a machine without installed MS Office? How do I import from Excel to a DataSet using Microsoft.Office.Interop.Excel? How can I make SQL case sensitive string comparison on MySQL? Better way to cast object to int Write Array to Excel Range How do I properly clean up Excel interop objects? How to call shell commands from Ruby

Examples related to dataset

How to convert a Scikit-learn dataset to a Pandas dataset? Convert floats to ints in Pandas? Convert DataSet to List C#, Looping through dataset and show each record from a dataset column How to add header to a dataset in R? How I can filter a Datatable? Stored procedure return into DataSet in C# .Net Looping through a DataTable adding a datatable in a dataset How to fill Dataset with multiple tables?

Examples related to excel-interop

Closing Excel Application Process in C# after Data Access Optimal way to Read an Excel file (.xls/.xlsx) How to fix 'Microsoft Excel cannot open or save any more documents' How do I import from Excel to a DataSet using Microsoft.Office.Interop.Excel? HRESULT: 0x800A03EC on Worksheet.range How to count the number of rows in excel with data? System.Runtime.InteropServices.COMException (0x800A03EC) How do I auto size columns through the Excel interop objects? Exporting the values in List to excel