I'm using an OleDbConnection to create an Excel file:
String bewegungenDateiname = System.IO.Path.ChangeExtension(System.IO.Path.GetTempFileName(), ".xls");
string strConnectionString = #"Provider=Microsoft.Jet.OLEDB.4.0;Data Source="
+ System.IO.Path.GetDirectoryName(bewegungenDateiname) + #"\" + System.IO.Path.GetFileName(bewegungenDateiname)
+ #";Extended Properties='Excel 8.0;HDR=YES'";
using (System.Data.OleDb.OleDbConnection objConn = new System.Data.OleDb.OleDbConnection(strConnectionString))
using (System.Data.OleDb.OleDbCommand cmd = new System.Data.OleDb.OleDbCommand("", objConn))
{
objConn.Open();
cmd.CommandText = "CREATE TABLE [Test] ([MyDecimal] DECIMAL NULL)";
cmd.ExecuteNonQuery();
cmd.Parameters.Clear();
Decimal value = 12.34m;
cmd.Parameters.AddWithValue("#P01", value);
cmd.CommandText = "INSERT INTO [Test$] ([MyDecimal]) VALUES (#P01)";
cmd.ExecuteNonQuery();
}
System.Diagnostics.Process.Start(bewegungenDateiname);
Now when Excel 2013 opens the Excel file it will Show:
MyDecimal
1234
So in my case Excel is losing the dot. Now I'm running a german Version of Windows/Office and if I use the following line to add the Parameter it will work:
cmd.Parameters.AddWithValue("#P01", value.ToString());
German localization of numbers uses a colon instead of the dot to separate the fractions from the number value (meaning 12,34 instead of 12.34). So it seems the OleDbConnection uses the wrong culture variant to write the Excel file?
I fear my Version might break with a different Version of Excel or a different locale - is there a way to fix this and get decimal values to Excel without such risks?
I would use some other way to create Excel files, if it is without this flaw.
With Excel 2013 try using the following:
strConnectionString = String.Format("Provider=Microsoft.ACE.OLEDB.12.0;Data Source={0};Extended Properties=""Excel 12.0;HDR=No;IMEX=1""", _filePath)
I have no idea if it will solve the problem.
Related
My VB.NET app currently allows me to convert CSV files to a datatable thanks to the code provided by David in this question I posted: Previous Question
Now I am trying to allow .XLSX files to be imported to a datatable as well. Currently the code looks like this:
Private Function ConvertCSVToDataTable(ByVal path As String) As DataTable
Dim dt As DataTable = New DataTable()
Using con As OleDb.OleDbConnection = New OleDb.OleDbConnection()
Try
If System.IO.Path.GetExtension(path) = ".csv" Then
con.ConnectionString = String.Format("Provider={0};Data Source={1};Extended Properties=""Text;HDR=YES;FMT=Delimited""", "Microsoft.Jet.OLEDB.4.0", IO.Path.GetDirectoryName(path))
ElseIf System.IO.Path.GetExtension(path) = ".xlsx" Then
con.ConnectionString = String.Format("Provider={0};Data Source={1};Extended Properties=""Excel 12.0 XML;HDR=Yes;""", "Microsoft.ACE.OLEDB.12.0", IO.Path.GetDirectoryName(path))
End If
Using cmd As OleDb.OleDbCommand = New OleDb.OleDbCommand("SELECT * FROM " & IO.Path.GetFileName(path), con)
Using da As OleDb.OleDbDataAdapter = New OleDb.OleDbDataAdapter(cmd)
con.Open()
da.Fill(dt)
con.Close()
End Using
End Using
Catch ex As Exception
Console.WriteLine(ex.ToString())
Finally
If con IsNot Nothing AndAlso con.State = ConnectionState.Open Then
con.Close()
End If
End Try
End Using
Return dt
End Function
However, when I run the code using the .XLSX file, I get the following error:
{"The Microsoft Office Access database engine cannot open or write to
the file 'C:\Users\XSLXFilePath'. It is already opened exclusively by
another user, or you need permission to view and write its data."}
The file is not open anywhere else to my knowledge. And the app also runs fine when .CSV file is put through it instead. How do I get the app to properly work for .XLSX, or any Excel file format?
I think that the error is that from the connection string and the OLEDB Command:
ConnectionString
You don't have to use IO.Path.GetDirectoryName(path) it returns the directory name, you have to provide the file full path:
con.ConnectionString = String.Format("Provider={0};Data Source={1};Extended Properties=""Excel 12.0 XML;HDR=Yes;""", "Microsoft.ACE.OLEDB.12.0", path)
Refer to this link for excel connectionstring generation function: import data from excel 2003 to dataTable
OLEDB Command
You must provide the Worksheet name in the Command instead of the Filename:
Using cmd As OleDb.OleDbCommand = New OleDb.OleDbCommand("SELECT * FROM [Sheet1$]" , con)
If the Sheet names is dynamic and you have to get the first sheet in the excel file:
Dim dbSchema as DataTable = con.GetOleDbSchemaTable (OleDbSchemaGuid.Tables, null)
Dim firstSheetname as String = dbSchema.Rows(0)("TABLE_NAME").ToString
Using cmd As OleDb.OleDbCommand = New OleDb.OleDbCommand("SELECT * FROM [" & firstSheetname & "]" , con)
References
Reading from excel using oledbcommand
Read and Write Excel Documents Using OLEDB
Use can use the following connection string for .xlsx file.
I have used it and working fine.
P_FIle = ( File Name with path )
P_Con_Str = "Provider=Microsoft.ACE.OLEDB.12.0;Data Source=" & P_File & ";Extended Properties=""Excel 12.0 XML;HDR=Yes;"""
I'm trying to figure out why the behavior I'm seeing and the "documented" behavior are different. I've read both of these articles:Read and Write Excel Documents Using OLEDB and Working with MS Excel(xls / xlsx) Using MDAC and Oledb and this is text from the second link.
If you read in the second link it says:
To Retrieve Schema Information of Excel Workbook :
You can get the worksheets that are present in the excel workbook using GetOleDbSchemaTable. Use the following snippet.
DataTable dtSchema = null;
dtSchema = conObj.GetOleDbSchemaTable(
OleDbSchemaGuid.Tables, new object[] { null, null, null, "TABLE" });
Here dtSchema will hold the list of all workbooks. Say we have two workbooks : wb1, wb2. The above code will return a list of wb1, wb1$,wb2,wb2$. We need to filter out $ elements.
However when I run this code I only get "wb1$ and wb2$". I can easily remove the $ in code but I'm trying to make sure I'm not going to have code that breaks when I put it on a different computers/OS/environment and it behaves as is documented. Can somebody tell my what or if something changed since these were written or if I'm missing some key piece. Something to note this is being developed in VS2015, Windows 7 Pro, and Office 2010 installed.
//Connection String
//string connstring = "Provider=Microsoft.ACE.OLEDB.12.0;Data Source=" + path + ";Extended Properties='Excel 8.0;HDR=NO;IMEX=1';"; // Extra blank space cannot appear in Office 2007 and the last version. And we need to pay attention on semicolon.
//string connstring = Provider = Microsoft.JET.OLEDB.4.0; Data Source = " + path + "; Extended Properties = 'Excel 8.0;HDR=NO;IMEX=1'; "; //This connection string is appropriate for Office 2007 and the older version. We can select the most suitable connection string according to Office version or our program.
using (OleDbConnection conn = new OleDbConnection(_connectionString))
{
conn.Open();
//DataTable sheetNames = conn.GetOleDbSchemaTable(OleDbSchemaGuid.Tables, new object[] { null, null, null, "TABLE" }); //Get All Sheets Name
DataTable sheetNames = conn.GetOleDbSchemaTable(OleDbSchemaGuid.Tables, null); //Get All Sheets Name
// Loop through all Sheets to get data
foreach (DataRow dr in sheetNames.Rows)
{
string sheetName = dr["TABLE_NAME"].ToString();
//if (!sheetName.EndsWith("$"))
// continue;
Debug.Print(sheetName);
}
return sheetNames;
Thanks
dbl
I have an Excel document and one column is of type text. Some cells contain combinations of letters and digits, while other cells contain numbers only. I found out that if the cell value contains only digits, the reader interprets the values in the cells as a long integer and it truncates it. So, rather than getting "120500923", I get back "1.20501e+008"
Here is my code:
OleDbConnection myConnection = new OleDbConnection("Provider=Microsoft.Jet.OLEDB.4.0;Data Source="myfile.xls";Extended Properties=\"Excel 8.0;HDR=NO;IMEX=1\"");
OleDbCommand myCommand = new OleDbCommand("Select * from [Sheet1];");
myConnection.Open();
myCommand.Connection = myConnection;
OleDbDataReader myReader = myCommand.ExecuteReader();
string[] myLine = new string[5];
while (myReader.Read())
{
for (int i = 0; i < 5; i++) //read the first 5 columns
{
myLine[i] = (string)myReader[i].ToString();
}
}
How can I instruct the reader to treat all the cell values as strings and not as numbers? I prefer not to modify the excel spreadsheet, because it is edited by people and I want to keep it simple.
Thanks,
Nick
After some googling and experimenting, I found out some useful stuff.
I discovered that if I replace the connection string from Jet to ACE, the cell value will be considered a string.
So, I changed the first line in the code as below:
OleDbConnection myConnection = new OleDbConnection("Provider=Microsoft.ACE.OLEDB.12.0;Data Source=\"myfile.xls\";Extended Properties=\"Excel 12.0;HDR=YES;IMEX=1\"");
Since my computer is a Windows 10/64 bit, the default MDAC driver installed was 64 bit. I had to uninstall it and install the 32 bit version (I use SharpDevelop and apparently I can only compile 32 bit applications), from http://www.microsoft.com/en-us/download/details.aspx?id=13255. I am able to use version 12, even if I don't have Office 2003 or later installed.
This is my first attempt to read an Excel 2007 file via ADO.net, and I must be missing something b/c when I try to run the query, I get an exception. When I started looking, it's b/c the table (worksheet) isn't there. Can someone please tell me what I'm doing wrong?
Here is my code:
string cs = #"Provider=Microsoft.ACE.OLEDB.12.0;Data Source=My File.xlsx;Extended Properties=""Excel 12.0;IMEX=1;""";
using (OleDbConnection con = new OleDbConnection(cs))
{
con.Open();
string query = "SELECT * FROM [Sheet1$]";
OleDbCommand cmd = new OleDbCommand(query, con);
OleDbDataAdapter adapter = new OleDbDataAdapter(cmd);
DataTable dt = new DataTable();
DataTable worksheets = con.GetSchema("Tables");
adapter.Fill(dt);
.
.
.
}
Take a look at the accepted answer here
The First Column of the excel file to put in string variable C#?
It works for Excel 2003 but I think it could easily be adapted to work with 2007.
I'm working on a SharePoint workflow, and the first step requires me to open an Excel workbook and read two things: a range of categories (from a range named, conveniently enough, Categories) and a category index (in the named range CategoryIndex). Categories is a list of roughly 100 cells, and CategoryIndex is a single cell.
I'm using ADO.NET to query the workbook
string connectionString =
"Provider=Microsoft.ACE.OLEDB.12.0;" +
"Data Source=" + temporaryFileName + ";" +
"Extended Properties=\"Excel 12.0 Xml;HDR=YES\"";
OleDbConnection connection = new OleDbConnection(connectionString);
connection.Open();
OleDbCommand categoryIndexCommand = new OleDbCommand();
categoryIndexCommand.Connection = connection;
categoryIndexCommand.CommandText = "Select * From CategoryIndex";
OleDbDataReader indexReader = categoryIndexCommand.ExecuteReader();
if (!indexReader.Read())
throw new Exception("No category selected.");
object indexValue = indexReader[0];
int categoryIndex;
if (!int.TryParse(indexValue.ToString(), out categoryIndex))
throw new Exception("Invalid category manager selected");
OleDbCommand selectCommand = new OleDbCommand();
selectCommand.Connection = connection;
selectCommand.CommandText = "SELECT * FROM Categories";
OleDbDataReader reader = selectCommand.ExecuteReader();
if (!reader.HasRows || categoryIndex >= reader.RecordsAffected)
throw new Exception("Invalid category/category manager selected.");
connection.Close();
Don't judge the code itself too harshly; it's been through a lot. Anyway, the first command never executes correctly. It doesn't throw an exception. It just returns an empty data set. (HasRows is true, and Read() returns false, but there is no data there) The second command works perfectly. These are both named ranges.
They are populated differently, however. There's a web service call that fills up Categories. Those values are displayed in a dropdown box. The selected index goes into CategoryIndex. After hours of banging my head, I decided to write a couple of lines of code so that the dropdown's value goes into a different cell, then I copy the value using a couple of lines of C# into CategoryIndex, so that the data is set identically. That turned out to be a blind alley, too.
Am I missing something? Why would one query work perfectly and the other fail to return any data?
I have found the issue. Excel was apparently unable to parse the value in the cell, so it was returning nothing. What I had to do was adjust the connection string to the following:
string connectionString =
"Provider=Microsoft.ACE.OLEDB.12.0;" +
"Data Source=" + temporaryFileName + ";" +
"Extended Properties=\"Excel 12.0 Xml;HDR=NO;IMEX=1\"";
It would have been helpful if it would have thrown an exception or given any indication of why it was failing, but that's beside the point now. The option IMEX=1 tells Excel to treat all values as strings only. I'm quite capable of parsing my own integers, thankyouverymuch, Excel, so I didn't need its assistance.