I am trying to insert multiple records into SQL database. SQL table contains `smalldatetime` column. Every record is for one hour period, so when you want to insert timespan for, eg. 5 hours, you fill in 5 records into database.

Code looks something like this:

```
int flag = 0;
try{
   if (String.Empty.Equals(tboxFromTime.Text)){
      MessageBox.Show("Error!", "Error", MessageBoxButtons.OK, MessageBoxIcon.Information);
      return;
   }
   DateTime n, m;
   if (!DateTime.TryParse(tboxFromTime.Text, out n)){
      MessageBox.Show("Error!");
      return;
   }
   FormMain.connection.Open();
   command = new SqlCommand();
   command.Connection = FormMain.connection;
   string classParam, personParam, startParam;
   classParam = "class";
   personParam = "person";
   startParam = "start";

   command.CommandText = "INSERT INTO Reservations (resClassID, resPersonID, resStart) VALUES (@class, @person, @start)";
   command.Parameters.AddWithValue("@class", int.Parse(cboxRoomID.Text.Substring(4)));
   command.Parameters.AddWithValue("@person", int.Parse(cboxPersonSelection.Text.Substring(0, 2).Trim()));
   command.Parameters.AddWithValue("@start", DateTime.Parse(cboxWeekDate.Text + " " + n.ToShortTimeString() + ":00"));
   if (!String.Empty.Equals(tboxToTime.Text)){
      if (!DateTime.TryParse(tboxToTime.Text, out m)){
         MessageBox.Show("Error!");
         return;
      }
      else if(DateTime.Compare(m.AddHours(-1), n) > 0){
             TimeSpan timeDiff = m - n;
             int intDiff = timeDiff.Hours;
             for (int i = 1; i < intDiff; i++){
                 classParam = "class" + i.ToString();
                 personParam = "person" + i.ToString();
                 startParam = "start" + i.ToString();
                 command.CommandText += ", " + String.Format("(@{0}, @{1}, @{2})", classParam, personParam, startParam);

                 command.Parameters.AddWithValue(String.Format("@{0}", classParam), int.Parse(cboxRoomID.Text.Substring(4)));
                 command.Parameters.AddWithValue(String.Format("@{0}", personParam), int.Parse(cboxPersonSelection.Text.Substring(0, 2).Trim()));
                 command.Parameters.AddWithValue(String.Format("@{0}", startParam), DateTime.Parse(cboxWeekDate.Text + " " + n.AddHours(i).ToShortTimeString() + ":00"));
             }
         }
     }

   flag = command.ExecuteNonQuery();
   if (flag == 1) { MessageBox.Show("Uspelo!"); }
   }

```

When executing for one hour period it all goes well, but for any timespan it cracks. Command Text string for a few hours is like this:

```
INSERT INTO Reservations (resClassID, resPersonID, resStart) VALUES (@class, @person, @start), (@class1, @person1, @start1), (@class2, @person2, @start2), (@class3, @person3, @start3)

```

but, again I get this type of error message:

Incorrect syntax near ','.

Can anyone figure out what is the problem?