//update station
private void updateStationbutton_Click(object sender, EventArgs e)
{
if (updateStationTextBox.Text == "")
{
MessageBox.Show("Select a record");
}
else
{
//try updating station with corresponding id and refresh data
try
{
String station = updateStationTextBox.Text;
DbHandler.UpdateStation(stationId, station);
DisplayData();
ClearData();
MessageBox.Show("Successfully data updated!");
}
catch (Exception exc)
{
Console.WriteLine(exc);
}
}
}
private void removeButton_Click(object sender, EventArgs e)
{
string sRemoveTextbox = idRemoveTextbox.Text;
if (sRemoveTextbox == "")
{
MessageBox.Show("Select a record!");
}
else
{
DialogResult dialog = MessageBox.Show("Are you sure you want to delete this record?", "Confirmation",
MessageBoxButtons.YesNoCancel);
if (dialog == DialogResult.Yes)
{
DbHandler.DeleteDistance(id);
RefreshDataGridView();
MessageBox.Show("Successfully data deleted");
}
else if (dialog == DialogResult.No)
{
MessageBox.Show("Nothing's been changed");
}
}
}
private void addButton_Click(object sender, EventArgs e)
{
try
{
connString.Open();
}
catch (Exception ex)
{
Console.WriteLine("Exception in DBHandler", ex);
}
selectedLine1 = line1Combobox.SelectedValue.ToString();
selectedLine2 = line2Combobox.SelectedValue.ToString();
selectedStation = station1Combobox.SelectedValue.ToString();
selectedStation2 = station2Combobox.SelectedValue.ToString();
string sCheckDistanceTextBox = addDistanceTextbox.Text.ToString();
int intDistanceTextBox;
var intCheckDistanceTextBox = Int32.TryParse(addDistanceTextbox.Text, out intDistanceTextBox);
// reading from distance table checking for already added distance between two stations with same train lines
string myQuery = "Select Count(*) From Distance Where Station1 = @station1 " +
"AND Station2 = @station2 AND Line1 = @line1 AND Line2 = @line2 ";
SqlCommand myCommand = new SqlCommand(myQuery, connString);
myCommand.Parameters.AddWithValue("@station1", selectedStation);
myCommand.Parameters.AddWithValue("@station2", selectedStation2);
myCommand.Parameters.AddWithValue("@line1", selectedLine1);
myCommand.Parameters.AddWithValue("@line2", selectedLine2);
//reading the data
int rows = (int)myCommand.ExecuteScalar();
//if there is 1 matching then dont add
if (rows > 0)
{
MessageBox.Show("Station 1: " + selectedStation + " for line: " + selectedLine1 +
" and Station 2: " + selectedStation2 + " for line 2: " + selectedLine2
+ " are already been added!");
errorOccured = 1;
connString.Close();
}
try
{
connString.Open();
}
catch (Exception ex)
{
Console.WriteLine("Exception in DBHandler", ex);
}
// reading from distance table checking for already added distance between two stations but selected in opposite comboboxes
//so there is no duplicates in either stations with same train lines
string myQuery2 = "Select Count(*) From Distance Where Station1 = @sStation2 " +
"AND Station2 = @sStation1 AND Line1 = @sLine1 AND Line2 = @sLine2 ";
SqlCommand myCommand2 = new SqlCommand(myQuery2, connString);
myCommand2.Parameters.AddWithValue("@sStation2", selectedStation2);
myCommand2.Parameters.AddWithValue("@sStation1", selectedStation);
myCommand2.Parameters.AddWithValue("@sLine1", selectedLine1);
myCommand2.Parameters.AddWithValue("@sLine2", selectedLine2);
//reading the data
int rows2 = (int)myCommand2.ExecuteScalar();
//if there is 1 matching then dont add
if (rows2 > 0)
{
MessageBox.Show("second error: Station 1: " + selectedStation + " for line: " + selectedLine1 +
" and Station 2: " + selectedStation2 + " for line 2: " + selectedLine2
+ " are already been added!");
connString.Close();
}
//distance textbox cannot be empty
else if (sCheckDistanceTextBox == "")
{
MessageBox.Show("You need to enter some value");
}
//if the distance is lower than 0 then output error
else if (intDistanceTextBox == 0 || intDistanceTextBox < 0)
{
MessageBox.Show("Distance should be more than '0'");
}
//if the lines aren't the same
else if (!selectedLine1.Equals(selectedLine2))
{
MessageBox.Show("Not allowed to choose different lines!");
}
//if the stations are the same
else if (selectedStation.Equals(selectedStation2))
{
MessageBox.Show("Not allowed to choose same stations!");
}
else
{
if (errorOccured == 1)
{
errorOccured = 0;
}
else
{
DialogResult dialog = MessageBox.Show("Are you sure you want to continue?", "Confirmation",
MessageBoxButtons.YesNoCancel);
if (dialog == DialogResult.Yes)
{
//add the data to the database
DbHandler.AddDistance(selectedStation, selectedStation2, selectedLine1,
selectedLine2, sCheckDistanceTextBox);
RefreshDataGridView();
MessageBox.Show("Data successfully added!");
}
else if (dialog == DialogResult.No)
{
MessageBox.Show("Nothing's been changed");
}
}
//close connection
connString.Close();
}
}
