Question

I am trying to read an Excel file with C# and I keep getting this error: oledbexception cannot update. database or object is read-only on the line. Any ideas?

        string connStr = ConfigurationManager.ConnectionStrings["SiteSqlServer"].ConnectionString;
        SqlConnection conn = new SqlConnection(connStr);
        //file upload path

        string path = FileUpload1.PostedFile.FileName;
        //Create connection string to Excel work book
        string excelConnectionString = @"Provider=Microsoft.Jet.OLEDB.4.0;Data Source=" + FileUpload1.PostedFile.FileName + ";Extended Properties=\"Excel 8.0;HDR=Yes;IMEX=1\"";
        //Create Connection to Excel work book
        OleDbConnection excelConnection = new OleDbConnection(excelConnectionString);
        //Create OleDbCommand to fetch data from Excel
        OleDbCommand cmd = new OleDbCommand("Select [Coupon], [First Name], [Last Name] from [Sheet1$]",excelConnection);
        excelConnection.Open();
        OleDbDataReader dReader;
        dReader = cmd.ExecuteReader();
        SqlBulkCopy sqlBulk = new SqlBulkCopy(conn);
        //Give your Destination table name
        sqlBulk.DestinationTableName = "CPC_Coupons";
        sqlBulk.WriteToServer(dReader);
        excelConnection.Close();

Thanks!

Answer 1

Please see the following code if that might help in your scenario:

  public static class DatabaseManager
    {
        //set connection string for SQL Server Express Edition
        static string connString = @"Data Source=LOCALHOST\SQLEXPRESS;Initial Catalog=DocumentStore;Integrated Security=True;Pooling=False";


        //method to save document to database
        public static bool SaveDocumentToDatabase(MemoryStream msDocument, DocumentType docType, string documentName)
        {
            //keep track of the save status 
            bool isSaved = false;

            //create database connection
            SqlConnection sqlConnection = new SqlConnection(connString);
            try
            {
                sqlConnection.Open();
            }
            catch (Exception ex)
            {
                Settings.LogException(ex);
                Console.WriteLine("Unable to open database connection");
                isSaved = false;
            }

            string commandText = "INSERT INTO Documents (DocumentType, DocumentName, DocumentContent, CreateDate) VALUES('" + docType + "','" + documentName + "', @DocumentContent ,'" + DateTime.Now + "')";
            SqlCommand sqlCommand = new SqlCommand(commandText, sqlConnection);
            sqlCommand.Parameters.AddWithValue("DocumentContent", msDocument.ToArray());
            try
            {
                sqlCommand.ExecuteNonQuery();
                Console.WriteLine("Document saved successfully");
                isSaved = true;
            }
            catch(Exception ex)
            {
                Console.WriteLine("Unable to save the document to database");
                Settings.LogException(ex);
                isSaved = false;
            }

            //close database connect
            sqlConnection.Close();


            return isSaved;
        }

    public static bool LoadDocumentFromDataBase(DocumentType docType)
    {
         //keep track of the retrieve status 
        bool isRetrieved = false;


        //create database connection
        SqlConnection sqlConnection = new SqlConnection(connString);
        try
        {
            sqlConnection.Open();
        }
        catch(Exception ex)
        {
            Console.WriteLine("Unable to open database connection");
            Settings.LogException(ex);
            isRetrieved = false;
        }


        string commandText = "SELECT * FROM Documents WHERE DocumentType ='" + docType + "'";

        SqlDataAdapter sqlDataAdapter = new SqlDataAdapter(commandText, sqlConnection);
        SqlCommand sqlCommand = new SqlCommand(commandText, sqlConnection);

        DataTable dtDocuments = new DataTable();

        try
        {
            sqlDataAdapter.Fill(dtDocuments);
            Console.WriteLine("Document retrieved successfully");
            isRetrieved = true;
        }
        catch(Exception ex)
        {
            Console.WriteLine("Unable to retrieve documents from database");
            Settings.LogException(ex);
            isRetrieved = false;
        }
   }
}