How can I save a DataTable to a .DBF?

Question

I've been working on a program to read a dbf file, mess around with the data, and save it back to dbf. The problem that I am having is specifically to do with the writing portion.

    private const string constring = "Driver={Microsoft dBASE Driver (*.dbf)};"
                                   + "SourceType=DBF;"
                                   + "DriverID=277;"
                                   + "Data Source=¿;"
                                   + "Extended Properties=dBASE IV;";
    private const string qrystring = "SELECT * FROM [¿]";
    public static DataTable loadDBF(string location)
    {
        string filename = ConvertLongPathToShort(Path.GetFileName(location));
        DataTable table = new DataTable();
        using(OdbcConnection conn = new OdbcConnection(RTN(constring, filename)))
        {
            conn.Open();
            table.Load(new OdbcCommand(RTN(qrystring, filename), conn).ExecuteReader());
            conn.Close();
        }
        return table;
    }

    private static string RTN(string stmt, string tablename)
    { return stmt.Replace("¿", tablename); }

    [DllImport("Kernel32", CharSet = CharSet.Auto)]
    static extern Int32 GetShortPathName(
    String path,                // input string
    StringBuilder shortPath,    // output string
    Int32 shortPathLength);     // StringBuilder.Capacity

    public static string ConvertLongPathToShort(string longPathName)
    {
        StringBuilder shortNameBuffer;
        int size;

        shortNameBuffer = new StringBuilder();

        size = GetShortPathName(longPathName, shortNameBuffer, shortNameBuffer.Capacity);
        if (size >= shortNameBuffer.Capacity)
        {
            shortNameBuffer.Capacity = size + 1;
            GetShortPathName(longPathName, shortNameBuffer, shortNameBuffer.Capacity);
        }

        return shortNameBuffer.ToString();
    }

This is what I'm working with. I've tried a number of methods to write a new file, none of them productive. To be honest, while normally I would be an advocate of form and function, I just want the damn thing to work, this app is supposed to do one very specific thing, it's not going to simulate weather.

-=# Edit #=-

I've since discontinued the app due to time pressure, but before I scrapped it I realised that the particular format of dbf I was working with had no primary key information. This of course meant that I had to essentially read the data out to DataTable, mess with it, then wipe all the records in the dbf and insert everything from scratch. Screw that for a lark.

Answer 1

What kind of dbf file are you working with? (There are several, e.g. dBase, FoxPro etc that are not 100% compatible.) I have gotten this to work with the Microsoft Visual FoxPro OleDB Provider from C#, you might give that a shot instead of using the dBase ODBC driver.

Answer 2

I don't understand clearly. I am doing homework about write/update or inset a record from dataset to DBF file in C#. But I don't know and I can't ask any body. So, now I ask you and I ask someone who know about this problem. Please, thanks

Answer 3

Using ADO.Net to read and write dbf files turns out to be really slow so I would suggest you use an alternative approach.

One option would be to use the old DAO 3.6 library. This is much faster and just as compatible, but depends on a com object to work.

A better approach would be to use the open source DBFExporter component. It may require some code to set up (you need a class with properties that describe your recordset and the properties must have certain attributes set) but after that it works really well. It is fast to use but it doesn't read dbf files. The component is licences under the LGPL so you should be able to use it in commercial code.