How to upload Access(.mdb) table data to SQL Server with C#

I have a .mdb file inside which there are some tables. I want to upload one of the table's data into my SQL server's database table.

My SQL Server's database table name: Tab1

Access database table name: Customer

By the following C# code it is possible to transfer the data from access to sql server.

string str = "INSERT INTO Tab1(name,addr,NetworkID,UnitName) SELECT * FROM OPENROWSET";
str += "('Microsoft.Jet.OLEDB.4.0','E:\\Attn\\Upload_acss.mdb';'admin';'',Customer)";
SqlCommand sqlcom = new SqlCommand(str, connection);

   try
   {
        connection.Open();// connection is a SqlConnection type object which created before
        sqlcom.ExecuteNonQuery();
        connection.Close();
 

        Label1.ForeColor = System.Drawing.Color.Green;
        Label1.Text = "Inserted...";
   }
   catch (Exception ex) { Response.Write(ex.ToString()); }