如何检查开始时间范围和结束时间是否属于我的数据表中存储的另一个开始时间和结束时间

Question

为我的日程安排系统保存一些日程表后，我需要创建一个代码，如果我的其他日程安排（开始时间 + 结束时间 + 房间 + 与同一位教师）属于已从数据表中保存的其他计划的范围。

我试着写一个代码，但它有一个问题，在得到落在范围内的时间之后，即使房间和老师不一样，它也算真实......但是如果时间只应该是真的属于同一房间 + 同一位老师的时间范围。

这是我的代码：

String str1;

str1 = "select * from Scheduling where Timein = '" + DDStartTime.SelectedItem.ToString() + "' OR TimeOut = '" + DDEndTime.SelectedItem.ToString() + "' AND Day ='" + SchedDayDD.SelectedItem.ToString() + "'";

string checkuser6 = "select count(*) from Scheduling where Timein = '" + DDStartTime.SelectedItem.ToString() + "' OR TimeOut = '" + DDEndTime.SelectedItem.ToString() + "' AND Day ='" + SchedDayDD.SelectedItem.ToString() + "'AND RoomNumber = '" + RoomDDSched.SelectedItem.ToString() + "'";

SqlCommand comm6 = new SqlCommand(checkuser6, con);
temp7 = Convert.ToInt32(comm6.ExecuteScalar().ToString());

string checkuser7 = "select count(*) from Scheduling where Timein = '" + DDStartTime.SelectedItem.ToString() + "' OR TimeOut = '" + DDEndTime.SelectedItem.ToString() + "' AND Day ='" + SchedDayDD.SelectedItem.ToString() + "'AND Name = '" + SchedNameDD.SelectedItem.ToString() + "'";

 SqlCommand comm7 = new SqlCommand(checkuser6, con);
 temp8 = Convert.ToInt32(comm7.ExecuteScalar().ToString());
 SqlCommand commms = new SqlCommand(str1, con);
 SqlDataReader reads = commms.ExecuteReader();

 if(temp8 != 0 )
 {
      num9 = 1;
 }

 if (temp7 == 0)
 {
      num10 = 0;
 }
 else
 {
      if (reads.Read())
      {
           tempstart = reads["Timein"].ToString();
           tempend = reads["TimeOut"].ToString();
           tempdays = reads["Day"].ToString();
           num10 = 1;
           reads.Close();
      }

      TimeSpan starts = TimeSpan.Parse(tempstart);
      TimeSpan ends = TimeSpan.Parse(tempend);

      string tempstarttime = DDStartTime.SelectedValue.ToString();
      string tempsendtime = DDEndTime.SelectedValue.ToString();

      TimeSpan nowstart = TimeSpan.Parse(tempstarttime.Remove(tempstarttime.Length - 3));
      TimeSpan nowend = TimeSpan.Parse(tempsendtime.Remove(tempsendtime.Length - 3));

      if (((nowstart > starts) || (nowstart < ends)) || ((nowend > starts) || (nowend < ends)))
      {
           num11 = 1;
      }
 }

 num12 = num9 + num10 + num11;
 reads.Close();

 if (num12 == 3)
 {
      Page.ClientScript.RegisterStartupScript(this.GetType(), "Scripts", "<script>alert('Range Between Time Conflict Detected')</script>");
 }
 else
 {
      //Save to database
 }