I'm having a problem opening a DBF file - I need to open it, read everything and process it. I tried several solutions (ODBC/OLEDB), several connection string, but nothing worked so far.
The problem is, when I execute the SQL command to get everything from the file, nothing gets returned - no rows. What's even more odd, the content of the DBF file being opened get deleted.
See the code I have:
public override bool OpenFile(string fileName, string subFileName = "")
{
OleDbConnection con = new OleDbConnection("Provider=Microsoft.Jet.OLEDB.4.0;Data Source=" + Path.GetDirectoryName(fileName) + ";Extended Properties=dBASE IV;User ID=;Password=;");
try
{
if (con.State == ConnectionState.Closed) { con.Open(); }
OleDbDataAdapter da = new OleDbDataAdapter("select * from " + Path.GetFileName(fileName), con);
DataSet ds = new DataSet();
da.Fill(ds);
con.Close();
int i = ds.Tables[0].Rows.Count;
return true;
}
catch
{
return false;
}
}
I debugged the code and watched the file being opend in Windows Explorer. When it reached this line:
da.Fill(ds);
the size of the file dropped to only a few Bytes (from hundreds of kB).
My next thought was to make the DBF file read only. That however cause an "unexpected exception from an external driver".
So my question is - what the heck? I'm sure the file is not corrupt, it is a direct export from some DB. (No, I do not have access to that DB). I can also open that file in MS Office no problem.
I cannot share the DBF file - it contains confidential data.
Two things... just because its a .DBF file extension might night mean its a Dbase IV file. It might actually be that of Visual Foxpro. That said, I would look into downloading and installing the Visual Foxpro OleDB driver from Microsoft download. Next, the OleDbConnection is pointing to the path that has the actual tables (you already have that).
The query itself, shouldn't care about the extension, so I would change your call to get just then name via "Path.GetFileNameWithoutExtension"
It might be a combination of the two.
Connection string for VFP provider
"Provider=VFPOLEDB.1;Data Source=" + FullPathToDatabase
This is not the exact answer but it will help you to find the issue.
Try to give an inline connection string and select query to make sure problem is not with building those. Catch the exception and check the details of it.
OleDbConnection con = new OleDbConnection("Provider=Microsoft.Jet.OLEDB.4.0;Data Source=c:\folder;Extended Properties=dBASE IV;User ID=;Password=;"); // give your path directly
try
{
con.Open();
OleDbDataAdapter da = new OleDbDataAdapter("select * from tblCustomers.DBF", con); // update this query with your table name
DataSet ds = new DataSet();
da.Fill(ds);
con.Close();
int i = ds.Tables[0].Rows.Count;
return true;
}
catch(Exception e)
{
var error = e.ToString();
// check error details
return false;
}
Related
I am developing an application to recover data from a DBF file.
I did research on the Internet that sent me to this link : enter link description here
I applied this code but nothing helps it doesn't work :/
string constr = #"Provider=Microsoft.Jet.OLEDB.4.0;Data Source=C:\Users\Test\users.dbf;Extended Properties=dBASE IV;User ID=;Password=MyPassword;";
using (OleDbConnection con = new OleDbConnection(constr))
{
var sql = "select * from users.dbf";
OleDbCommand cmd = new OleDbCommand(sql, con);
con.Open();
DataSet ds = new DataSet(); ;
OleDbDataAdapter da = new OleDbDataAdapter(cmd);
da.Fill(ds);
}
I pass this code in a Try and Catch and it returns me this error: Unable to start your application. The workgroup information file is missing or opened exclusively by another user.
the error is caused when trying to open the connection. However the file is neither opened nor used by anyone else.
thank you in advance ;)
Try to remove the file name in the connection string. According to the documentation, The "Data Source" property should only contain the path.
string constr = #"Provider=Microsoft.Jet.OLEDB.4.0;Data Source=C:\Users\Test;Extended Properties=dBASE IV;User ID=;Password=MyPassword;";
Firstly please don't mark it as duplicate I know it's been asked multiple times here but none of the links helped me.
I am trying to access database which is located on shared drive, also both the mdb file and the folder in which it is stored have full access to everyone. I have hosted my application on two different machines.
Below is the code to connect to access DB
OleDbDataAdapter dataAdapter = null;
DataTable dtAttendance = new DataTable();
try
{
string conStr = System.Configuration.ConfigurationManager.ConnectionStrings["AccessDBPath"].ToString();
using (OleDbConnection conn = new OleDbConnection("Provider=Microsoft.Jet.OLEDB.4.0;Mode= Share Deny None;Data Source= " + conStr))
{
conn.Open();
OleDbCommand cmd = new OleDbCommand(#"Select EmployeeId AS UserId,AttendanceDate , format(Int(Duration/60),'0') AS Duration,format(Duration Mod 60,'0') AS Remain FROM AttendanceLogs
where EmployeeId =" + userid.ToString() + " and Year(AttendanceDate)="+year+" and Month(AttendanceDate)="+month+" order by AttendanceDate desc", conn);
dataAdapter = new OleDbDataAdapter();
dataAdapter.SelectCommand = cmd;
dataAdapter.Fill(dtAttendance);
conn.Close();
}
}
catch(Exception ee)
{}
Only first time when I tested it, it worked properly and thereafter it started throwing above error.
I am looking for a library which would do something like that:
Lib.Configure.Cells(...)
Lib.CreateExcelFileFromMyObject<MyObject>(myObject);
I believe a long ago I come across such library but cant remember it's name.
May be some one can point me to the right direction.
I know two ways to read or write excel files.
As already said you can access excel files through the office interop interface as described here. This method is slow, but you can do almost everything what you can do with the gui of excel.
Use the OleDb database interface. This possibility is much faster than the first one, but its restricted to data. So as far as i know it is not possible to read/write formatting e.g. some background color of a cell. With the following function you will get the entire data of a sheet of an excel file at once:
private DataSet ConnectAndLoad(string filepath, string sheet)
{
DataSet data_set = new DataSet();
OleDbConnection oledbConn = new OleDbConnection(String.Format("Provider=Microsoft.Ace.Oledb.12.0;Data Source={0};Extended Properties=\"Excel 8.0;HDR=Yes;IMEX=1;\"", filepath));
string query = "Select * From [" + sheet + "$]";
try
{
oledbConn.Open();
OleDbCommand oledbCmd = new OleDbCommand(query, oledbConn);
OleDbDataAdapter ole_da = new OleDbDataAdapter(oledbCmd);
ole_da.Fill(data_set);
}
catch (OleDbException ex)
{
// do some error catching
}
finally
{
oledbConn.Close();
}
return data_set;
}
you can use
using Microsoft.Office.Interop
namespace to access the ms products
For that first you need to do is add that reference to your project
I am trying to load data using following code.
string path = System.IO.Path.GetFullPath(uploadExcelFile.PostedFile.FileName);
string connString = "provider=Microsoft.ACE.OLEDB.12.0;Data Source=C:\\Users\\Rizwan shahid\\Desktop\\DataUpload\\Req.xls;Extended Properties=Excel 12.0;";
OleDbConnection oledbConn = new OleDbConnection(connString);
try
{
oledbConn.Open();
OleDbCommand cmd = new OleDbCommand("SELECT * FROM [Sheet1$]", oledbConn);
OleDbDataAdapter oleda = new OleDbDataAdapter();
oleda.SelectCommand = cmd;
DataSet ds = new DataSet();
oleda.Fill(ds, "Table");
return ds.Tables[0];
}
catch
{
return null;
}
finally
{
oledbConn.Close();
}
It was working on 32Bit operating system but when run this code on 64Bit OS it gives the following error
The Microsoft Access database engine could not find the object 'Sheet1$'. Make sure the object exists and that you spell its name and the path name correctly. If 'Sheet1$' is not a local object, check your network connection or contact the server administrator.
I am running VS in Administrator mode and found many solution like replace Sheet1 with file name or place file in C drive but still getting the same error.
you can download latest version here of Jet
http://www.microsoft.com/en-us/download/search.aspx?q=jet
This works (I start out with a 'dummy' path and then apply the real runtime path):
OleStringBuilder =
new OleDbConnectionStringBuilder(#"Provider=Microsoft.Jet.OLEDB.4.0;Data Source=C:\MyExcel.xls;Extended Properties='Excel 8.0;HDR=Yes;IMEX=1';");
OleStringBuilder.DataSource = MapPath(#"~\App_Data\MyExcelWorksheet.xls");
private void Form1_Load(object sender, EventArgs e)
{
GetDataTable(#"C:\Documents and Settings\agordon\Desktop\ACTIVITYEX.log");
}
public System.Data.DataTable GetDataTable(string strFileName)
{
System.Data.OleDb.OleDbConnection conn =
new System.Data.OleDb.OleDbConnection
("Provider=Microsoft.Jet.OleDb.4.0; Data Source = "
+ System.IO.Path.GetDirectoryName(strFileName)
+ ";Extended Properties = \"Text;HDR=YES;FMT=TabDelimited\"");
conn.Open();
string strQuery = "SELECT * FROM [" + System.IO.Path.GetFileName(strFileName) + "]";
System.Data.OleDb.OleDbDataAdapter adapter = new System.Data.OleDb.OleDbDataAdapter(strQuery, conn);
System.Data.DataTable ds = new System.Data.DataTable("CSV File");
adapter.Fill(ds);
return ds;
}
when THE SAME file is named .csv it does not give me an error; however when i rename it to .log it says Cannot update. Database or object is read-only. on adapter.Fill
is this a compiler error?
An old post, but I just stepped into that problem.
Please refer to this article : https://support.microsoft.com/en-us/kb/245407
Long story short : Jet Engine only accepts a few file extension when reading CSV File (Extended properties=TEXT,etc..).
Solutions :
rename your file in a temp folder when reading it
read it with another mecanism than JET (standard File.io.ReadAllLines)
Add the extension in the windows registry as pointed out by antonio Bukala
No, it's a not a compiler error. If anything it's an error from the OleDb Jet engine. I have ran into enough problems with Jet in the past so I usually avoid it. You might save yourself lots of debugging time by using TextFieldParser.
*.log is disabled extension, AFAIK only way is registry change on machine that will run this code, see MS Knowledge base article