public void RemoveLocation(ContactBookLogic contactbooklogic, long countLocation, SQLConnection sql, int value) { var CommandText = $"SELECT COUNT(l.LocationID) FROM locations l, contacts c WHERE {value} = c.LocationID AND {value} = l.LocationID;"; // check ob locationID von der zu löschenden location in contacts vorhanden ist - wenn ja -> nicht löschen long count = sql.ExecuteScalar(CommandText); CommandText = $"SELECT * FROM locations WHERE LocationID = {value}"; long c = sql.ExecuteScalar(CommandText); if (count == 0 && c > 0) { CommandText = $"DELETE FROM locations WHERE LocationID = {value};"; sql.ExecuteNonQuery(CommandText); //TODOL: location successfully deleted message } //TODOL: all messages for : alternatives else 1. no location with index value found 2. you can not delete location that is associated to a contact 3. invalid input }
//----------------------------------------REMOVE METHOD------------------------------------------------------------------------------ public void RemoveContact(ContactBookLogic contactbooklogic, long countContact, SQLConnection sql, int value) { var CommandText = $"DELETE FROM contacts WHERE ContactID = '{value}';"; sql.ExecuteNonQuery(CommandText); //TODOL: contact successfully deleted message + invalid input message }