private void Course_Load(object sender, EventArgs e)
{
dataGridView1.Hide();
SubjectComboBox.Hide();
StudentComboBox.Hide();
TeacherNameLabel.Hide();
Hide_Eval_And_Insert_Marks_And_Update_Marks_Code();
try
{
//sqlConnection1.Open();
SqlCommand cmd = new SqlCommand();
cmd.Connection = sqlConnection1;
cmd.CommandType = CommandType.Text;
cmd.CommandText = "Select course_name from Course";
SqlDataReader reader = cmd.ExecuteReader();
if (reader.HasRows)
{
while (reader.Read())
{
CourseComboBox.Items.Add(reader.GetString(0));
}
}
reader.Close();
//sqlConnection1.Close();
}
catch (Exception ex)
{
MessageBox.Show(ex.Message);
}
}
// Replaced Method
private void SubjectComboBox_SelectedValueChanged(object sender, EventArgs e)
{
StudentComboBox.Show();
StudentComboBox.Items.Clear();
Hide_Eval_And_Insert_Marks_And_Update_Marks_Code();
dataGridView1.Rows.Clear();
try
{
//sqlConnection1.Open();
Data_Grid_View_Initialization();
SqlCommand cmd = new SqlCommand();
cmd.Connection = sqlConnection1;
cmd.CommandType = CommandType.Text;
cmd.CommandText = "SELECT teacher_name from Teacher where teacher_id = (Select teacher_id from Subject where subject_name = @sub_name)";
cmd.Parameters.AddWithValue("@sub_name", SubjectComboBox.SelectedItem);
SqlDataReader reader = cmd.ExecuteReader();
while (reader.Read())
{
TeacherNameLabel.Text = "Welcome Mrs. " + reader.GetString(0);
}
TeacherNameLabel.Show();
reader.Close();
cmd.CommandText = "Select student_name from Student where course_id = (SELECT course_id from Subject where subject_name = @s_name)";
cmd.Parameters.AddWithValue("@s_name", SubjectComboBox.SelectedItem);
reader = cmd.ExecuteReader();
while (reader.Read())
{
StudentComboBox.Items.Add(reader.GetString(0));
}
reader.Close();
//sqlConnection1.Close();
}
catch (Exception ex)
{
MessageBox.Show(ex.Message);
}
}
//Replaced Method
private void CourseComboBox_SelectedValueChanged(object sender, EventArgs e)
{
SubjectComboBox.Show();
TeacherNameLabel.Hide();
dataGridView1.Hide();
StudentComboBox.Items.Clear();
SubjectComboBox.Items.Clear();
Hide_Eval_And_Insert_Marks_And_Update_Marks_Code();
try
{
SubjectLabel.Text = "Select Subject for " + CourseComboBox.SelectedItem;
int selected_course_id = CourseComboBox.SelectedIndex + 1;
SqlCommand cmd = new SqlCommand();
cmd.Connection = sqlConnection1;
cmd.CommandType = CommandType.Text;
cmd.CommandText = "SELECT subject_name from Subject where course_id =@c_id";
cmd.Parameters.AddWithValue("@c_id", selected_course_id);
SqlDataReader reader = cmd.ExecuteReader();
if (reader.HasRows)
{
while (reader.Read())
{
SubjectComboBox.Items.Add(reader.GetString(0));
}
}
reader.Close();
//sqlConnection1.Close();
}
catch (Exception ex)
{
MessageBox.Show(ex.Message);
}
}