Having trouble with SQL Delete on SQL Server using C# - sql-server

Question

I am running this code but it throws an exception and I am not sure why. Any help would be appreciated. I checked the ID and it was the right ID for the record.
protected void DeleteSQLDB(int id)
{
String ConnString = GetConnectAccess();
try
{
using (SqlConnection m_dbConnection = new SqlConnection(ConnString))
{
String sql = "DELETE FROM tblStudent WHERE ID=" + id;
using (SqlCommand cmd = new SqlCommand(sql, m_dbConnection))
{
m_dbConnection.Open();
cmd.ExecuteNonQuery();
m_dbConnection.Close();
}
}
}
catch (Exception ex)
{
Response.Redirect("somwhere");
}
finally
{
}
}

Answer 1

I solved the problem. The reason was that the record was referenced in other tables so I had to remove the references before I could remove the record. Thanks user7396598 for advice about running query manually. This is the code which removes the conversations first and then the student record:
//This deletes the archived student, First any conversations need to be deleted before the record can be removed.
protected void DeleteSQLDB(object id,String studentID)
{
// Response.Redirect(studentID);
String ConnString = GetConnectAccess();
try
{
using (SqlConnection m_dbConnection = new SqlConnection(ConnString))
{
String sql = "DELETE FROM tblConversations WHERE StudentID=#studentID";
using (SqlCommand cmd = new SqlCommand(sql, m_dbConnection))
{
cmd.Parameters.AddWithValue("#studentID", studentID);
m_dbConnection.Open();
cmd.ExecuteNonQuery();
}
}
}
catch (Exception ex)
{
}
finally
{
DeleteSQLDB2(id);
}
}
protected void DeleteSQLDB2(object id)
{
// Response.Redirect(studentID);
String ConnString = GetConnectAccess();
try
{
using (SqlConnection m_dbConnection = new SqlConnection(ConnString))
{
String sql = "DELETE FROM tblStudent WHERE ID=#ID";
using (SqlCommand cmd = new SqlCommand(sql, m_dbConnection))
{
cmd.Parameters.AddWithValue("#ID", id);
m_dbConnection.Open();
cmd.ExecuteNonQuery();
}
}
}
catch (Exception ex)
{
}
finally
{
Response.Redirect("studentgrid.aspx");
}
}