批量插入到 SQL Server 2012 C# 中

>我的列表中有大约一百万条记录。对于列表中的每个，我查询数据库以获取基于id的修改日期。一旦我得到它，它就会在插入或更新它的情况下进行测试..但是有没有办法批量（一次或批量）插入或更新..？？

foreach (No_kemi no_list in newforSQL)
{
    DateTime eModifiedDate = no_list.ModifiedDate.Value;
    string Id = no_list.ID.ToString();
    String selectQuery = "SELECT ModifiedDate FROM NO_table WHERE ID = '" + Id + "'";
    DateTime? dbmoddate = null;
    using (SqlCommand selectCommand = new SqlCommand(selectQuery, connection))
    {
        // Use the above SqlCommand object to create a SqlDataReader object.
        using (SqlDataReader rdr = selectCommand.ExecuteReader())
        {
            while (rdr.Read())
            {
                dbmoddate = (DateTime)rdr["ModifiedDate"];
            }
        }
    }
    string eType = null;
    string SubGUID = null;
    string trimSubKey = no_list.SubscriberKey;
    try
    {
        if ((trimSubKey.Length > 3) && (trimSubKey != ""))
        {
            if (trimSubKey.Contains(","))
            {
                string[] values = trimSubKey.Split(',');
                SubGUID = values[0];
                eType = values[1];
            }
            else 
            { 
                SubGUID = trimSubKey; 
                eType = ""; 
            }
        }
        else 
        { 
             SubGUID = ""; 
             eType = ""; 
        }
    }
    catch (Exception ex)
    {
        logger.Error("Error : " + ex.Message );
    }
    if (dbmoddate == null)
    {
        DateTime no_listinsetdate = DateTime.Now;
        String insertQuery = "INSERT INTO NO_table (CreatedDate, ModifiedDate, ID, eType, SubGUID, DbDate) VALUES (@CreatedDate, @ModifiedDate, @ID, @eType, @SubGUID, @DbDate,)";
        using (SqlCommand insertCommand = new SqlCommand(insertQuery, connection))
        {
             insertCommand.Parameters.AddWithValue("@CreatedDate", no_list.CreatedDate);
             insertCommand.Parameters.AddWithValue("@ModifiedDate", no_list.ModifiedDate);
             insertCommand.Parameters.AddWithValue("@ID", no_list.ID);
             insertCommand.Parameters.AddWithValue("@eType", eType);
             insertCommand.Parameters.AddWithValue("@SubGUID", SubGUID);
             insertCommand.Parameters.AddWithValue("@DbDate", no_listinsetdate);
             insertCommand.ExecuteNonQuery(); // execute the query
         }
    }
    else if (eModifiedDate > dbmoddate)
    {
        DateTime no_listinsetdate = DateTime.Now;
        String updateQuery = "UPDATE  NO_table SET CreatedDate = @CreatedDate, ModifiedDate = @ModifiedDate, ID = @ID, eType = @eType, SubGUID = @SubGUID, DbDate = @DbDate WHERE ID = '" + Id + "'";
        using (SqlCommand updateCommand = new SqlCommand(updateQuery, connection))
        {
            updateCommand.Parameters.AddWithValue("@CreatedDate", no_list.CreatedDate);
            updateCommand.Parameters.AddWithValue("@ModifiedDate", no_list.ModifiedDate);
            updateCommand.Parameters.AddWithValue("@ID", no_list.ID);
            updateCommand.Parameters.AddWithValue("@eType", eType);
            updateCommand.Parameters.AddWithValue("@SubGUID", SubGUID);
            updateCommand.Parameters.AddWithValue("@DbDate", no_listinsetdate);
            updateCommand.ExecuteNonQuery(); // execute the query
        }
    }
}

任何加快过程的方法...完成操作需要花费大量时间...或者有时我收到超时错误...

感谢