Question

I am using SqlBulkCopy object to write a datatable into an sql server table. However, everytime I recheck my database it remains intact with no changes. A

I have tried to do Google search to determine my problem but i am unable to resolve it.

The datatable came from an .xls file.

public static DataTable dt = new DataTable();

private void ExportToGrid(String path, String filen)
    {
        int idx = filen.IndexOf(".");
        string tf = filen.Remove(idx, 4);

        OleDbConnection MyConnection = null;
        DataSet DtSet = null;
        OleDbDataAdapter MyCommand = null;
        MyConnection = new OleDbConnection("provider=Microsoft.Jet.OLEDB.4.0; Data Source='" + path + "';Extended Properties=Excel 8.0;");

        ArrayList TblName = new ArrayList();

        MyConnection.Open();
        DataTable schemaTable = MyConnection.GetOleDbSchemaTable(OleDbSchemaGuid.Tables, new object[] { null, null, null, "TABLE" });
        foreach (DataRow row in schemaTable.Rows)
        {
            TblName.Add(row["TABLE_NAME"]);
        }

        MyCommand = new System.Data.OleDb.OleDbDataAdapter("select * from [" + TblName[0].ToString() + "]", MyConnection);
        DtSet = new System.Data.DataSet();

        MyCommand.Fill(DtSet);
        MyCommand.FillSchema(DtSet, SchemaType.Source);

        DataTable dt = new DataTable();
        dt = DtSet.Tables[0];
        Session["dt"] = dt;
        int x = dt.Rows.Count;
        MyConnection.Close();

        if (dt.Rows.Count > 0)
        {
            theGridView.DataSource = dt;
            theGridView.DataBind();
        }

        if (System.IO.File.Exists(path))
        {
            System.IO.File.Delete(path);
        }

    }

This is my writer function

private void StartImport()
    {
        string servername = server;
        string database = database;
        string tbl = "dbo.LinkDb";

        Stopwatch sw = new Stopwatch();
        sw.Start();
        SqlBulkCopy bulkCopy = new SqlBulkCopy("Data Source=" + servername + ";Initial Catalog=" + database + ";Integrated Security=SSPI", SqlBulkCopyOptions.TableLock);
        bulkCopy.DestinationTableName = tbl;
        bulkCopy.WriteToServer(dt);
        sw.Stop();
        lblResult.Visible = true;
        lblResult.Text = (sw.ElapsedMilliseconds / 1000.00).ToString();
    }

Below are the screenshot of the tables stored in my sql server. I assure you that I have been complying to Case Sensitive rules.

There was no exception thrown and average time elapsed is 0.018 – 0.020 secs

Appreciate any helps.

Thank you

Answer 1

Based on the code you have posted, you are writing an empty datatable to the database. Your “ExportToGrid” method fills dt, a DataTable declared locally, which loses scope outside of the method. Your write function is calling the static DataTable dt which is a new datatable.

Does dt need to be static? it seems as though this could be declared as

private DataTable dt;

then inside “ExportToGrid” instead of declaring another DataTable just instantiate the already declared dt rather than declaring a new one

dt = new DataTable();

Alternatively you could extract the DataTable straight from the GridView during the write Method:

DataTable dt = (DataTable)theGridView.DataSource;
bulkCopy.WriteToServer(dt);

This removes the need for variables outside of the scope of the method.

Lastly since you are storing your datatable within the session (I am not generally an advocate of storing large amounts of data in session variables but without knowing the specifics of your site I cannot really pass judgement), you could use the following:

DataTable dt = (DataTable)Session["dt"];
bulkCopy.WriteToServer(dt);