database.php

<?php
// This file is part of Moodle - http://moodle.org/
//
// Moodle is free software: you can redistribute it and/or modify
// it under the terms of the GNU General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.
//
// Moodle is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
// GNU General Public License for more details.
//
// You should have received a copy of the GNU General Public License
// along with Moodle.  If not, see <http://www.gnu.org/licenses/>.

/**
 * persistence layer utility class
 *
 * @package assignsubmission_dta
 * @license   http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
 * @copyright Gero Lueckemeyer and student project teams
 */
class DbUtils {

    /**
     * Summary database table name.
     */
    private const TABLE_SUMMARY = "assignsubmission_dta_summary";
    /**
     * Result database table name.
     */
    private const TABLE_RESULT = "assignsubmission_dta_result";

    private const TABLE_RECOMMENDATIONS = "assignsubmission_dta_recommendations";

    public static function get_recommendations_from_database(int $assignmentid, int $submissionid): array {
        global $DB,$USER;
        $userid = $USER->id;
    
        // Schritt 1: Alle Empfehlungen abrufen
        $records = $DB->get_records(self::TABLE_RECOMMENDATIONS, [
            'assignment_id' => $assignmentid,
            'submission_id' => $submissionid,
        ]);
    
        // Schritt 2: Modul-ID für 'assign' abrufen
        $module = $DB->get_record('modules', ['name' => 'assign'], 'id');
        if (!$module) {
            // Fehlerbehandlung, falls das Modul nicht gefunden wird
            return $records;
        }
        $moduleid = $module->id;
    
        // Schritt 3: Überprüfe jeden Datensatz
        foreach ($records as $key => $record) {
            // Hol den Namen der Übung aus dem Datensatz
            $exercisename = $record->exercise_name;
    
            // Suche das Assignment mit diesem Namen
            $assign = $DB->get_record('assign', ['name' => $exercisename], 'id');
    
            if ($assign) {
                // Hole die Kursmodul-ID (coursemoduleid) für dieses Assignment
                $cm = $DB->get_record('course_modules', [
                    'module' => $moduleid,
                    'instance' => $assign->id
                ], 'id');
    
                if ($cm) {