private void saveDataSet(DataTable dtEx)
        {
            //删除原有的列
            SQLHelper.Update("delete  from ods");

            using (System.Data.SqlClient.SqlConnection sqlconnt = new System.Data.SqlClient.SqlConnection(connString))
            {
                sqlconnt.Open();

                DataSet           dst = new DataSet();
                SqlDataAdapter    ad  = new SqlDataAdapter("select top 1 * from ods where 1<>1", sqlconnt);
                SqlCommandBuilder cmd = new SqlCommandBuilder(ad);
                ad.Fill(dst, tableName);
                DataTable dtSourcet = dst.Tables[tableName];
                //创建没有的列表名
                List <string> diffcol = TableOperation.GetDiffColums(dtEx, dtSourcet);
                if (diffcol.Count > 0)//有不同的列
                {
                    TableOperation.AddTableColumn(tableName, connString, diffcol);
                }
            }

            SqlBulkCopyByDatatable(connString, tableName, dtEx);
        }