sqlbulkcopy from Excel via ACE.OLEDB truncates text to 255 chars

Question

Pretty straight-forward import using SqlBulkCopy:

string excelConnectionString = @"Provider=Microsoft.ACE.OLEDB.12.0;Data Source=" + filePath + ";Extended Properties=\"Excel 12.0 Xml;HDR=YES;IMEX=1;\"";
using (OleDbConnection excelConnection = new OleDbConnection(excelConnectionString))
{
    excelConnection.Open();
    OleDbCommand cmd = new OleDbCommand("Select " + fileID.ToString() + " as [FileID], * from [Sheet1$] where [Text] IS NOT NULL", excelConnection);
    OleDbDataReader dReader = cmd.ExecuteReader();

    using (SqlBulkCopy sqlBulk = new SqlBulkCopy(ConfigurationManager.ConnectionStrings["DBConnection"].ConnectionString))
    {
        sqlBulk.DestinationTableName = "table_name";
        sqlBulk.ColumnMappings.Add(0, "FileID");
        sqlBulk.ColumnMappings.Add(4, "Author");
        sqlBulk.ColumnMappings.Add(3, "Title");
        sqlBulk.ColumnMappings.Add(1, "Body");
        sqlBulk.ColumnMappings.Add(2, "PublishedDate");
        sqlBulk.BulkCopyTimeout = 600;
        sqlBulk.WriteToServer(dReader);
    }
}

Data goes in, no problem. Except the first column, which is mapped to Body (nvarchar(max)) gets truncated to 255 characters. I looked around, found some references to workaround that involves changing a registry setting. Set value to 0 to force full scan, not just first 8 rows, which is Excel's default, but that didn't help even after reboot. Looking for other ideas. Thank you.

Answer 1

I used ODBC instead of the OLEDB and it doesn't truncate the values to 255 symbols anymore:

OdbcConnection con = new OdbcConnection(@"Driver={Microsoft Excel Driver
(*.xls)};DBQ=c:\temp\testbook.xls");
OdbcCommand cmd = new OdbcCommand(@"SELECT * FROM [Workbook1$]");
cmd.Connection = con;
OdbcDataAdapter da = new OdbcDataAdapter(cmd);
DataSet ds = new DataSet();
da.Fill(ds);

you can use 2007 format driver to access XLSX files: .... Driver={Microsoft Excel Driver (*.xls, *.xlsx, *.xlsm, *.xlsb)} …