将日期从日历添加到SQL server 2008

我正在asp.net c#中的一个项目中工作，我从两个日历中获取日期，并将它们存储在指定为SprintsN表中的datetime的数据库字段中，sql server 2008数据库。但是我得到了一个异常

例外:

insert into SprintsN (S_Duration, s_status, P_ID StartDate,EstEndDate)值("1周","不完整","5","2015-05-01 12:00:00’,‘2015-05-0712:00:00");System.Data.SqlClient。SqlException (0x80131904):错误"开始日期"附近的语法。在System.Data.SqlClient.SqlConnection。OnError (SqlException异常,breakConnection, Action ' 1 wrapCloseInAction) at

代码:

日历事件:

 protected void Calendar2_SelectionChanged(object sender, EventArgs e)
 {
     EstDate = Calendar2.SelectedDate.ToString("yyyy-MM-dd hh:mm:ss");
     EstDateBox.Text = EstDate;
     Calendar2.Visible = false;
  }
  protected void Calendar1_SelectionChanged(object sender, EventArgs e)
  {  
      startdate = Calendar1.SelectedDate.ToString("yyyy-MM-dd hh:mm:ss");
      SDate.Text = startdate;
      Calendar1.Visible = false;
  }

Sql数据库存储处理:

String query="";
try { 
    query = "insert into SprintsN (S_Duration, S_Staus, P_ID StartDate,EstEndDate) values('" + SprintDurBox.Text + "', 'incomplete','" + p_ID + "','"+startdate+"','"+EstDate+"');";
    SqlConnection con = new SqlConnection(str);
    SqlCommand com = new SqlCommand(query, con);
    con.Open();
    if (com.ExecuteNonQuery() == 1)
    {
        SprintStatus.Text = "Sprint Successfully Saved";
    }
    else
    {
        SprintStatus.Text = "Sprint  not Saved";
    }
}
catch (Exception ex)
{
    Response.Write(query);
    Response.Write(ex.ToString());
}