Why does OleDbDataAdapter leave artifacts when filling a DataTable? - c#

I wrote some methods which are supposed to fetch a DataTable for each WorkSheet in a Excel file:
Step 1 is to get the names of all sheets included in a .xlsx file:
private static List<string> GetSheetNames(string filePath)
{
List<string> sheetNames = new List<string>();
DataTable dt = null;
try
{
OleDbConnection connection = new OleDbConnection("provider=Microsoft.ACE.OLEDB.12.0;Data Source='" + filePath + "';Extended Properties='Excel 12.0 Xml;HDR=YES;'");
connection.Open();
dt = connection.GetOleDbSchemaTable(OleDbSchemaGuid.Tables, null);
if (dt == null)
{
return null;
}
// Add the sheet name to the string array.
foreach (DataRow row in dt.Rows)
{
sheetNames.Add(row["TABLE_NAME"].ToString());
}
}catch(Exception ex)
{
MessageBox.Show(ex.Message);
}
return sheetNames;
}
Step 2 is to read every sheet and return an according DataTable:
private static DataTable ReadExcelSheet(string filePath,string sheetName)
{
DataTable table = new DataTable();
ValidateSheetName(ref sheetName);
try
{
OleDbConnection connection;
DataSet DtSet;
OleDbDataAdapter cmd;
connection = new OleDbConnection("provider=Microsoft.ACE.OLEDB.12.0;Data Source='" + filePath + "';Extended Properties='Excel 12.0 Xml;HDR=YES;'");
cmd = new OleDbDataAdapter("select * from ["+sheetName+"]", connection);
cmd.TableMappings.Add("Table", sheetName.Replace("$",string.Empty));
DtSet = new DataSet();
cmd.Fill(DtSet);
table = DtSet.Tables[0];
connection.Close();
}
catch (Exception ex)
{
MessageBox.Show(ex.ToString());
}
return table;
}
Both methods are called from this last method which returns a List<DataTable>:
private static List<DataTable> ConvertExcelToTables(string filePath)
{
List<string> sheetNames = GetSheetNames(filePath);
List<DataTable> tableList = new List<DataTable>();
foreach(string sheetName in sheetNames)
{
tableList.Add(ReadExcelSheet(filePath,sheetName));
}
return tableList;
}
There is also a little helper method which should be irrelevant for the question:
private static void ValidateSheetName(ref string sheetName)
{
sheetName = sheetName.EndsWith("$") ? sheetName : sheetName + "$";
}
If I take one sheet from a example file it looks like this:
Now no matter if I just look into the DataTable while debugging or if I bind it as a DataSource of a DataGridView the result looks a little weird:
My guess is that this might have to do with Excel sheets beginning counting with 1 not with 0. But even if this is the case I can't really think of a solution. Or did I miss something. Actually this is a pity because this seems to be a clean solution imo.

No, the problem is caused by
HDR=YES;
in your connection string.
Change it to
HDR=NO;
HDR=YES means that the first line of your Excel sheets is assumed to contain the fields' names of your table. But this is not the case with the sheet shown as an example. Indeed the OleDb provider cannot determine the name of the second column (it's blank) and thus it assigns the default value (the letter F followed by the progressive number of the column)
You could find a lot of examples and explanations about connectionstrings for excel at connectionstrings.com

Related

Excel to DataGridView

Additional information: The Microsoft Office Access database engine could not find the object 'C:\Users\username\Documents\sampleData.xls'. Make sure the object exists and that you spell its name and the path name correctly.
The Error is highlighted at
theDataAdapter.Fill(spreadSheetData);
Here's the sample data I used (tried in .csv , .xls , .xlsx )
Name Age Status Children
Johnny 34 Married 3
Joey 21 Single 1
Michael 16 Dating 0
Smith 42 Divorced 4
Here's the code associated:
using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Windows.Forms;
using System.IO;
using System.Data.OleDb;
namespace uploadExcelFile
{
public partial class Form1 : Form
{
public Form1()
{
InitializeComponent();
}
private void btnImport_Click(object sender, EventArgs e)
{
var frmDialog = new System.Windows.Forms.OpenFileDialog();
if (frmDialog.ShowDialog() == System.Windows.Forms.DialogResult.OK)
{
string strFileName = frmDialog.FileName;
System.IO.FileInfo spreadSheetFile = new System.IO.FileInfo(strFileName);
scheduleGridView.DataSource = spreadSheetFile.ToString();
System.Diagnostics.Debug.WriteLine(frmDialog.FileName);
System.Diagnostics.Debug.WriteLine(frmDialog.SafeFileName);
String name = frmDialog.SafeFileName;
String constr = String.Format(#"Provider=Microsoft.ACE.OLEDB.12.0;Data Source={0};Extended Properties=""Excel 12.0 Xml;HDR=YES""", frmDialog.FileName);
OleDbConnection myConnection = new OleDbConnection(constr);
OleDbCommand onlineConnection = new OleDbCommand("SELECT * FROM [" + frmDialog.FileName + "]", myConnection);
myConnection.Open();
OleDbDataAdapter theDataAdapter = new OleDbDataAdapter(onlineConnection);
DataTable spreadSheetData = myConnection.GetOleDbSchemaTable(OleDbSchemaGuid.Tables, null);
theDataAdapter.Fill(spreadSheetData);
scheduleGridView.DataSource = spreadSheetData;
}
}
}
}
scheduleGridView is the DataGridViews name, & btnImport is the name for the import Button.
I've installed 2007 Office System Driver: Data Connectivity Components; which gave me the AccessDatabaseEngine.exe, but from there I've been stuck here without understanding how to get around this. It should go without saying that the filepath is correct in its entirety. There is no odd characters in the path name either (spaces, underlines, etc)
Mini Update :: (another dead end it seems like)
Although the initial error says, "could not find the object 'C:\Users\username\Documents\sampleData.xls'"
In the Debugger the exception is read as
When I look at details the exception as "C:\Users\username\Documents\sampleData.xls"
So I thought the error was that it wasn't taking the path as a literal, but this article C# verbatim string literal not working. Very Strange backslash always double
Shows very clearly that that is not my issue.
I am guessing you may be mistaken by what is returned from the following line of code…
DataTable spreadSheetData = myConnection.GetOleDbSchemaTable(OleDbSchemaGuid.Tables, null);
The DataTable returned from this line will have nine (9) columns (TABLE_CATALOG, TABLE_SCHEMA, TABLE_NAME, TABLE_TYPE, TABLE_GUID, DESCRIPTION, TABLE_PROPID, DATE_CREATED and DATE_MODIFIED). This ONE (1) DataTable returned simply “Describes” the worksheet(s) and named range(s) in the entire selected Excel workbook. Each row in this DataTable represent either a worksheet OR a named range. To distinguish worksheets from named ranges, the “TABLE_NAME” column in this DataTable has the name of the worksheet or range AND ends each “Worksheet” Name with a dollar sign ($). If the “TABLE_NAME” value in a row does NOT end in dollar sign, then it is a range and not a worksheet.
Therefore, when the line
OleDbDataAdapter theDataAdapter = new OleDbDataAdapter(onlineConnection);
Blows up and says it cannot file the “filename” error… is somewhat expected because this line is looking for a “worksheet” name, not a filename. On the line creating the select command…
OleDbCommand onlineConnection = new OleDbCommand("SELECT * FROM [" + frmDialog.FileName + "]", myConnection);
This is incorrect; you have already selected the filename and open the file with
String constr = String.Format(#"Provider=Microsoft.ACE.OLEDB.12.0;Data Source={0};Extended Properties=""Excel 12.0 Xml;HDR=YES""", frmDialog.FileName);
OleDbConnection myConnection = new OleDbConnection(constr);
myConnection.Open();
The correct OleDbCommand line should be…
OleDbCommand onlineConnection = new OleDbCommand("SELECT * FROM [" + sheetName + "]", myConnection);
The problem here is that the current code is not getting the worksheet names. Therefore, we cannot “select” the worksheet from the workbook then fill the adapter with the worksheet.
The other issue is setting the DataGridView’s DataSource to spreadSheetData… when you get the worksheet(s) from an Excel “Workbook”, you must assume there will be more than one sheet. Therefore a DataSet will work as a container to hold all the worksheets in the workbook. Each DataTable in the DataSet would be a single worksheet and it can be surmised that the DataGridView can only display ONE (1) of these tables at a time. Given this, below are the changes described along with an added button to display the “Next” worksheet in the DataGridView since there may be more than one worksheet in the workbook. Hope this makes sense.
int sheetIndex = 0;
DataSet ds = new DataSet();
public Form1() {
InitializeComponent();
}
private void btnImport_Click(object sender, EventArgs e) {
var frmDialog = new System.Windows.Forms.OpenFileDialog();
if (frmDialog.ShowDialog() == System.Windows.Forms.DialogResult.OK) {
String constr = String.Format(#"Provider=Microsoft.ACE.OLEDB.12.0;Data Source={0};Extended Properties=""Excel 12.0 Xml;HDR=YES""", frmDialog.FileName);
OleDbConnection myConnection = new OleDbConnection(constr);
myConnection.Open();
DataTable spreadSheetData = myConnection.GetOleDbSchemaTable(OleDbSchemaGuid.Tables, null);
string sheetName = "";
DataTable dt;
OleDbCommand onlineConnection;
OleDbDataAdapter theDataAdapter;
// fill the "DataSet" each table in the set is a worksheet in the Excel file
foreach (DataRow dr in spreadSheetData.Rows) {
sheetName = dr["TABLE_NAME"].ToString();
sheetName = sheetName.Replace("'", "");
if (sheetName.EndsWith("$")) {
onlineConnection = new OleDbCommand("SELECT * FROM [" + sheetName + "]", myConnection);
theDataAdapter = new OleDbDataAdapter(onlineConnection);
dt = new DataTable();
dt.TableName = sheetName;
theDataAdapter.Fill(dt);
ds.Tables.Add(dt);
}
}
myConnection.Close();
scheduleGridView.DataSource = ds.Tables[0];
setLabel();
}
}
private void setLabel() {
label1.Text = "Showing worksheet " + sheetIndex + " Named: " + ds.Tables[sheetIndex].TableName + " out of a total of " + ds.Tables.Count + " worksheets";
}
private void btnNextSheet_Click(object sender, EventArgs e) {
if (sheetIndex == ds.Tables.Count - 1)
sheetIndex = 0;
else
sheetIndex++;
scheduleGridView.DataSource = ds.Tables[sheetIndex];
setLabel();
}
I solved it. Well there was a workaround. I used the Excel Data Reader found in this thread: How to Convert DataSet to DataTable
Which led me to https://github.com/ExcelDataReader/ExcelDataReader
^ The readme was fantastic, just went to solution explorer, right click on references, manage NuGet Packages, select browse in the new box, enter ExcelDataReader, then in the .cs file be sure to include, "using Excel;" at the top, the code mentioned in the first link was essentially enough, but here's my exact code for those wondering.
var frmDialog = new System.Windows.Forms.OpenFileDialog();
if (frmDialog.ShowDialog() == System.Windows.Forms.DialogResult.OK)
{
/*string strFileName = frmDialog.FileName;
//System.IO.FileInfo spreadSheetFile = new System.IO.FileInfo(strFileName);
System.IO.StreamReader reader = new System.IO.StreamReader(strFileName);
*/
string strFileName = frmDialog.FileName;
FileStream stream = File.Open(strFileName, FileMode.Open, FileAccess.Read);
//1. Reading from a binary Excel file ('97-2003 format; *.xls)
IExcelDataReader excelReader = ExcelReaderFactory.CreateBinaryReader(stream);
//...
//2. Reading from a OpenXml Excel file (2007 format; *.xlsx)
//IExcelDataReader excelReader = ExcelReaderFactory.CreateOpenXmlReader(stream);
//...
//3. DataSet - The result of each spreadsheet will be created in the result.Tables
//DataSet result = excelReader.AsDataSet();
//...
//4. DataSet - Create column names from first row
excelReader.IsFirstRowAsColumnNames = true;
DataSet result = excelReader.AsDataSet();
DataTable data = result.Tables[0];
//5. Data Reader methods
while (excelReader.Read())
{
//excelReader.GetInt32(0);
}
scheduleGridView.DataSource = data;
excelReader.Close();

Failed to read correct date from excel (oledb)

We are trying to automate some of the processes that our done daily, for this we have made some Excel files which store the instruction for these processes. In a few such excel files we are using =TODAY() function to populate the cell with today's date.
Now while trying to read these excel files, I am not able to get the correct date in the datatable if excel is not opened at least once on a particular date. The date picked is from the last time the excel file was opened. This is causing a major problem while automating the problem at hand.
I would want to know if this can be achieved using OLEDB drivers and if not what other options are there?
This is the code for reading from the excel, the datasource is constructed at runtime.
private string excelObject = "Provider=Microsoft.Jet.OLEDB.4.0;Data Source={0};Extended Properties=\"Excel 8.0;HDR=YES\"";
public DataTable GetSchema()
{
DataTable dtSchema = null;
if (this.Connection.State != ConnectionState.Open) this.Connection.Open();
dtSchema = this.Connection.GetOleDbSchemaTable(OleDbSchemaGuid.Tables, new object[] { null, null, null, "TABLE" });
return dtSchema;
}
public DataTable ReadTable(string tableName, string criteria)
{
try
{
DataTable resultTable = null;
if (this.Connection.State != ConnectionState.Open)
{
this.Connection.Open();
onReadProgress(10);
}
string cmdText = "Select * from [{0}]";
if (!string.IsNullOrEmpty(criteria))
{
cmdText += " Where " + criteria;
}
OleDbCommand cmd = new OleDbCommand(string.Format(cmdText, tableName));
cmd.Connection = this.Connection;
OleDbDataAdapter adpt = new OleDbDataAdapter(cmd);
onReadProgress(30);
DataSet ds = new DataSet();
onReadProgress(50);
adpt.Fill(ds, tableName);
onReadProgress(100);
if (ds.Tables.Count == 1)
{
return ds.Tables[0];
}
else
{
return null;
}
}
catch
{
MessageBox.Show("Table Cannot be read");
return null;
}
}

Data not fills correctly in DataTable using OleDbDataAdapter

When I try to import excel sheet, it does not fetches some integer values. I am using DevExpress GridControl for exporting data from Grid. After export I change value of some cell's(which have blank value) to integer let's say 123 then on import it does not fetches that integer value in DataTable.
I have posted same issue on DevExpress support center "Export values in Improper Cell". They said the issue is from MSDN not by their control's. Please download the sample from given DevExpress link & also watch the video attached for more detailed information.
I have used following code for import.
private System.Data.DataTable GetDataTableFromFile(string fileName)
{
string query = string.Empty;
//// string connectionString = "provider=Microsoft.Jet.OLEDB.4.0;Data Source='" + fileName + "';Extended Properties=Excel 8.0;";
string connectionStringV12 = "Provider=Microsoft.ACE.OLEDB.12.0;Data Source={0};Extended Properties=Excel 12.0;";
string connectionStringV4 = "Provider=Microsoft.Jet.OLEDB.4.0;Data source={0};Extended Properties=Excel 8.0;";
System.Data.DataTable dataTable = new System.Data.DataTable();
OleDbConnection obedbConnection = new OleDbConnection(string.Format(connectionStringV4, fileName));
try
{
if (obedbConnection.State != ConnectionState.Open)
{
obedbConnection.Open();
}
}
catch (Exception)
{
////Diff. Connetion String
obedbConnection = new OleDbConnection(string.Format(connectionStringV12, fileName));
}
////Get First SheetName From Xls File
string sheetName = GetSheetNameFromFile(obedbConnection);
if (sheetName != null)
{
////Query for Reading all Data from File
query = "select * from [" + sheetName + "]";
}
if (!string.IsNullOrEmpty(query))
{
OleDbDataAdapter data = new OleDbDataAdapter(query, obedbConnection);
data.Fill(dataTable);
}
return dataTable;
}
/// <summary>
/// Gets First SheetName of excel File
/// </summary>
/// <param name="con">Connection object.</param>
/// <returns>return sheet name.</returns>
private string GetSheetNameFromFile(OleDbConnection con)
{
try
{
if (con.State != ConnectionState.Open)
{
con.Open();
}
var oledbTableSchema = con.GetOleDbSchemaTable(OleDbSchemaGuid.Tables, new object[] { null, null, null, "Table" });
if (oledbTableSchema.Rows.Count > 0)
{
string sheetName = oledbTableSchema.Rows[0].ItemArray[2].ToString();
if (string.IsNullOrEmpty(sheetName))
{
throw new Exception("Sheet Not Found");
}
return sheetName;
}
return string.Empty;
}
catch (Exception ex)
{
throw new Exception(ex.Message);
}
}
}
So, Can any one please help me to solve this issue?
Adding the IMEX = 1 property to my connection string, solved my issue.
string connectionStringV4 = "Provider=Microsoft.Jet.OLEDB.4.0;Data source={0};Extended Properties=Excel 8.0;IMEX=1;";
There is also similar behavior reported in the below thread
Not able to read integer in excel file consistantly
For more detailed answer please go to following link :
Data not fills correctly in DataTable using OleDbDataAdapter

How can I read the rows of an Excel csv or xls file into an ASP.NET app from a remote location using C#?

Here's my situation. I'm designing a program that takes Excel files (which may be in csv, xls, or xlsx format) from a remote network drive, processes the data, then outputs and stores the results of that process. The program provides a listbox of filenames that are obtained from the remote network drive folder using the method detailed in the accepted answer here. Once the user selects a filename from the listbox, I want the program to find the file and obtain the information from it to do the data processing. I have tried using this method to read the data from the Excel file while in a threaded security context, but that method just fails without giving any kind of error. It seems to not terminate. Am I going about this the wrong way?
Edit - (Final Notes: I have taken out the OleDbDataAdapter and replaced it with EPPlus handling.)
I was able to scrub sensitive data from the code, so here it is:
protected void GetFile(object principalObj)
{
if (principalObj == null)
{
throw new ArgumentNullException("principalObj");
}
IPrincipal principal = (IPrincipal)principalObj;
Thread.CurrentPrincipal = principal;
WindowsIdentity identity = principal.Identity as WindowsIdentity;
WindowsImpersonationContext impersonationContext = null;
if (identity != null)
{
impersonationContext = identity.Impersonate();
}
try
{
string fileName = string.Format("{0}\\" + Files.SelectedValue, #"RemoteDirectoryHere");
string connectionString = string.Format("Provider=Microsoft.ACE.OLEDB.14.0; data source={0}; Extended Properties=Excel 14.0;", fileName);
OleDbDataAdapter adapter = new OleDbDataAdapter("SELECT * FROM Sheet1", connectionString);
DataSet ds = new DataSet();
adapter.Fill(ds, "Sheet1");
dataTable = ds.Tables["Sheet1"];
}
finally
{
if (impersonationContext != null)
{
impersonationContext.Undo();
}
}
}
Additional Edit
Now xlsx files have been added to the mix.
Third Party
Third party solutions are not acceptable in this case (unless they allow unrestricted commercial use).
Attempts - (Final Notes: Ultimately I had to abandon OleDb connections.)
I have tried all of the different connection strings offered, and I have tried them with just one file type at a time. None of the connection strings worked with any of the file types.
Permissions
The User does have access to the file and its directory.
Your connection string might be the issue here. As far as I know, there isn't 1 that can read all xls, csv, and xlsx. I think you're using the XLSX connection string.
When I read xls, i use the following connection string:
#"Provider=Microsoft.Jet.OLEDB.4.0;Data Source=" + sFilePath + ";Extended Properties='Excel 8.0;HDR=YES;IMEX=1;'"
Having said that, I recommend using a 3rd party file reader/parser to read XLS and CSV since, from my experience, OleDbDataAdapter is wonky depending on the types of data that's being read (and how mixed they are within each column).
For XLS, try NPOI https://code.google.com/p/npoi/
For CSV, try http://www.codeproject.com/Articles/9258/A-Fast-CSV-Reader
For XLSX, try EPPlus http://epplus.codeplex.com/
I've had great success with the above libraries.
Is it really important that you use an OleDb interface for this? I've always done it with Microsoft.Office.Excel.Interop, to wit:
using System;
using Microsoft.Office.Interop.Excel;
namespace StackOverflowExample
{
class Program
{
static void Main(string[] args)
{
var app = new Application();
var wkbk = app.Workbooks.Open(#"c:\data\foo.xls") as Workbook;
var wksht = wkbk.Sheets[1] as Worksheet; // not zero-based!
for (int row = 1; row <= 100; row++) // not zero-based!
{
Console.WriteLine("This is row #" + row.ToString());
for (int col = 1; col <= 100; col++)
{
Console.WriteLine("This is col #" + col.ToString());
var cell = wksht.Cells[row][col] as Range;
if (cell != null)
{
object val = cell.Value;
if (val != null)
{
Console.WriteLine("The value of the cell is " + val.ToString());
}
}
}
}
}
}
}
As you will be dealing with xlsx extension, you should rather opt for the new connection string.
public static string getConnectionString(string fileName, bool HDRValue, bool WriteExcel)
{
string hdrValue = HDRValue ? "YES" : "NO";
string writeExcel = WriteExcel ? string.Empty : "IMEX=1";
return "Provider=Microsoft.ACE.OLEDB.12.0;" + "Data Source=" + fileName + ";" + "Extended Properties=\"Excel 12.0 xml;HDR=" + hdrValue + ";" + writeExcel + "\"";
}
Above is the code for getting the connection string. First argument expects the actual path for file location. Second argument will decide whether to consider first row values as column headers or not. Third argument helps decide whether you want to open the connection to create and write the data or simply read the data. To read the data set it to "FALSE"
public static ReadData(string filePath, string sheetName, List<string> fieldsToRead, int startPoint, int endPoint)
{
DataTable dt = new DataTable();
try
{
string ConnectionString = ProcessFile.getConnectionString(filePath, false, false);
using (OleDbConnection cn = new OleDbConnection(ConnectionString))
{
cn.Open();
DataTable dbSchema = cn.GetOleDbSchemaTable(OleDbSchemaGuid.Tables, null);
if (dbSchema == null || dbSchema.Rows.Count < 1)
{
throw new Exception("Error: Could not determine the name of the first worksheet.");
}
StringBuilder sb = new StringBuilder();
sb.Append("SELECT *");
sb.Append(" FROM [" + sheetName + fieldsToRead[0].ToUpper() + startPoint + ":" + fieldsToRead[1].ToUpper() + endPoint + "] ");
OleDbDataAdapter da = new OleDbDataAdapter(sb.ToString(), cn);
dt = new DataTable(sheetName);
da.Fill(dt);
if (dt.Rows.Count > 0)
{
foreach (DataRow row in dt.Rows)
{
string i = row[0].ToString();
}
}
cn.Dispose();
return fileDatas;
}
}
catch (Exception)
{
}
}
This is for reading 2007 Excel into dataset
DataSet ds = new DataSet();
try
{
string myConnStr = "";
myConnStr = "Provider=Microsoft.ACE.OLEDB.12.0;Data Source=MyDataSource;Extended Properties=\"Excel 12.0;HDR=YES\"";
OleDbConnection myConn = new OleDbConnection(myConnStr);
OleDbCommand cmd = new OleDbCommand("select * from [Sheet1$] ", myConn);
OleDbDataAdapter adapter = new OleDbDataAdapter();
adapter.SelectCommand = cmd;
myConn.Open();
adapter.Fill(ds);
myConn.Close();
}
catch
{ }
return ds;

Convert Excel Range to ADO.NET DataSet or DataTable, etc

I have an Excel spreadsheet that will sit out on a network share drive. It needs to be accessed by my Winforms C# 3.0 application (many users could be using the app and hitting this spreadsheet at the same time). There is a lot of data on one worksheet. This data is broken out into areas that I have named as ranges. I need to be able to access these ranges individually, return each range as a dataset, and then bind it to a grid.
I have found examples that use OLE and have got these to work. However, I have seen some warnings about using this method, plus at work we have been using Microsoft.Office.Interop.Excel as the standard thus far. I don't really want to stray from this unless I have to. Our users will be using Office 2003 on up as far as I know.
I can get the range I need with the following code:
MyDataRange = (Microsoft.Office.Interop.Excel.Range)
MyWorkSheet.get_Range("MyExcelRange", Type.Missing);
The OLE way was nice as it would take my first row and turn those into columns. My ranges (12 total) are for the most part different from each other in number of columns. Didn't know if this info would affect any recommendations.
Is there any way to use Interop and get the returned range back into a dataset?
I don't know about a built-in function, but it shouldn't be difficult to write it yourself. Pseudocode:
DataTable MakeTableFromRange(Range range)
{
table = new DataTable
for every column in range
{
add new column to table
}
for every row in range
{
add new datarow to table
for every column in range
{
table.cells[column, row].value = range[column, row].value
}
}
return table
}
I don't know what type of data you have.But for an excel data like shown in this link http://www.freeimagehosting.net/image.php?f8d4ef4173.png, you can use the following code to load into data table.
private void Form1_Load(object sender, EventArgs e)
{
try
{
DataTable sheetTable = loadSingleSheet(#"C:\excelFile.xls", "Sheet1$");
dataGridView1.DataSource = sheetTable;
}
catch (Exception Ex)
{
MessageBox.Show(Ex.Message, "");
}
}
private OleDbConnection returnConnection(string fileName)
{
return new OleDbConnection("Provider=Microsoft.Jet.OLEDB.4.0;Data Source=" + fileName + "; Jet OLEDB:Engine Type=5;Extended Properties=\"Excel 8.0;\"");
}
private DataTable loadSingleSheet(string fileName, string sheetName)
{
DataTable sheetData = new DataTable();
using (OleDbConnection conn = this.returnConnection(fileName))
{
conn.Open();
// retrieve the data using data adapter
OleDbDataAdapter sheetAdapter = new OleDbDataAdapter("select * from [" + sheetName + "]", conn);
sheetAdapter.Fill(sheetData);
}
return sheetData;
}
It's worth to take a look at NPOI when it comes to read/write Excel 2003 XLS files. NPOI is a life saver.
I think you'll have to iterate your range and create DataRows to put in your DataTable.
This question on StackOverflow provides more resources:
Create Excel (.XLS and .XLSX) file from C#
This method does not work well when the same column in the excel spread sheet contains both text and numbers. For instance, if Range("A3")=Hello and Range("A7")=5 then it reads only Hello and the value for Range("A7") is DBNULL
private void Form1_Load(object sender, EventArgs e)
{
try
{
DataTable sheetTable = loadSingleSheet(#"C:\excelFile.xls", "Sheet1$");
dataGridView1.DataSource = sheetTable;
}
catch (Exception Ex)
{
MessageBox.Show(Ex.Message, "");
}
}
private OleDbConnection returnConnection(string fileName)
{
return new OleDbConnection("Provider=Microsoft.Jet.OLEDB.4.0;Data Source=" + fileName + "; Jet OLEDB:Engine Type=5;Extended Properties=\"Excel 8.0;\"");
}
private DataTable loadSingleSheet(string fileName, string sheetName)
{
DataTable sheetData = new DataTable();
using (OleDbConnection conn = this.returnConnection(fileName))
{
conn.Open();
// retrieve the data using data adapter
OleDbDataAdapter sheetAdapter = new OleDbDataAdapter("select * from [" + sheetName + "]", conn);
sheetAdapter.Fill(sheetData);
}
return sheetData;
I made method which can take alredy filtered data from Excel
Taking filtered data in Range format
Worksheet sheet = null;
sheet = (Worksheet)context.cDocumentExcel.Sheets[requiredSheetName];
DataTable dt = new DataTable();
sheet.Activate();
sheet.UsedRange.Select();
List<Range> ranges = new List<Range>();
Range usedrange = sheet.UsedRange;
foreach (var oneRange in usedrange.SpecialCells(XlCellType.xlCellTypeVisible))
{
ranges.Add(oneRange);
}
dt = (_makeTableFromRange(ranges));
Converting from Range to DataTable
private static DataTable _makeTableFromRange(List<Range> ranges)
{
var table = new DataTable();
foreach (var range in ranges)
{
while (table.Columns.Count < range.Column)
{
table.Columns.Add();
}
while (table.Rows.Count < range.Row)
{
table.Rows.Add();
}
table.Rows[range.Row - 1][range.Column - 1] = range.Value2;
}
//clean from empty rows
var filteredRows = table.Rows.Cast<DataRow>().
Where(row => !row.ItemArray.All(field => field is System.DBNull ||
string.Compare((field as string).Trim(), string.Empty) ==
0));
table = filteredRows.CopyToDataTable();
return table;
}

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