diff --git a/system/coodle_data_migration.php b/system/coodle_data_migration.php
new file mode 100644
index 000000000..d3ec5bd27
--- /dev/null
+++ b/system/coodle_data_migration.php
@@ -0,0 +1,278 @@
+<?php
+/* Copyright (C) 2026 fhcomplete.org
+ *
+ * This program 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 2 of the
+ * License, or (at your option) any later version.
+ *
+ * This program 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 this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307, USA.
+ *
+ * Authors: Christian Paminger <christian.paminger@technikum-wien.at>,
+ *          Andreas Oesterreicher <andreas.oesterreicher@technikum-wien.at>
+ *
+ * Beschreibung:
+ * Dieses Skript prueft die gesamte Systemumgebung und sollte nach jedem Update gestartet werden.
+ * Geprueft wird: die Datenbank per "dbupdate_VERSION.php" auf aktualitaet, dabei werden fehlende Attribute angelegt.
+ */
+require_once('../config/system.config.inc.php');
+require_once('../include/basis_db.class.php');
+
+$db = new basis_db();
+
+// check if new coodle table is already populated
+$newSurveysCountQuery = "SELECT COUNT (*) FROM campus.tbl_coodle_surveys";
+$newSurveysCountResult = $db->db_query($newSurveysCountQuery);
+$newSurveysCount = $db->db_fetch_object($newSurveysCountResult)->count;
+if ($newSurveysCount > 0) {
+	exit;
+}
+
+// make sure id autoincrement is set to 1
+// $autoIncrementResetQuery = "ALTER TABLE campus.tbl_coodle_surveys AUTO_INCREMENT = 1";
+// $autoIncrementResetQuery = "ALTER SEQUENCE campus.seq_tbl_coodle_surveys_id RESTART WITH 1";
+// $db->db_query($autoIncrementResetQuery);
+
+// todo: include all surveys once code tested
+// getting old surveys...
+$surveysQuery = "SELECT * FROM campus.tbl_coodle WHERE coodle_id < 101";
+$surveysResult = $db->db_query($surveysQuery);
+while ($survey = $db->db_fetch_object($surveysResult)) {
+	// getting old timeslots before importing survey, as timeslot count affects max_selections value
+	$timeslotsData = [];
+	$selectedOldTimeslotId = null;
+	$timeslotsQuery = "SELECT * FROM campus.tbl_coodle_termin WHERE coodle_id = $survey->coodle_id";
+	$timeslotsResult = $db->db_query($timeslotsQuery);
+	while ($timeslot = $db->db_fetch_object($timeslotsResult)) {
+		$timeslotsData[] = [
+			"oldTimeslotId" => $timeslot->coodle_termin_id,
+			"startTime" => $timeslot->datum . " " . $timeslot->uhrzeit,
+		];
+		if ($timeslot->auswahl) {
+			$selectedOldTimeslotId = $timeslot->coodle_termin_id;
+		}
+	}
+
+	// importing survey...
+	$formattedDescription = formatDescription($survey->beschreibung ?? "");
+	$timeslotDuration = $survey->dauer ? $survey->dauer : 15;
+	if ($timeslotDuration % 5 !== 0) {
+		$timeslotDuration = $timeslotDuration - ($timeslotDuration % 5);
+	}
+	$areParticipantsAnonymized = $survey->teilnehmer_anonym ? "true" : "false";
+	$areSelectionsAnonymized = $survey->termine_anonym ? "true" : "false";
+	$maxSelections = count($timeslotsData) ? count($timeslotsData) : 1;
+	$completedAt = $survey->coodle_status_kurzbz === "abgeschlossen" ? "'$survey->updateamum'" : "NULL";
+	$canceledAt = $survey->coodle_status_kurzbz === "storniert" ? "'$survey->updateamum'" : "NULL";
+	$surveyInsertValues = [
+		"id" => $survey->coodle_id,
+		"creator_uid" => "'$survey->ersteller_uid'",
+		"title" => "'$survey->titel'",
+		"description" => "'$formattedDescription'",
+		"timeslot_duration" => $timeslotDuration,
+		"are_selections_anonymized" => $areSelectionsAnonymized,
+		"are_participants_anonymized" => $areParticipantsAnonymized,
+		"max_selections" => $maxSelections,
+		"selected_timeslot_id" => "NULL",
+		"ends_at" => "'$survey->endedatum'",
+		"completed_at" => $completedAt,
+		"canceled_at" => $canceledAt,
+		"created_at" => "'$survey->insertamum'",
+		"updated_at" => "'$survey->updateamum'",
+	];
+	$columnsString = "(" . implode(", ", array_keys($surveyInsertValues)) . ")";
+	$valuesString = "(" . implode(", ", array_values($surveyInsertValues)) . ")";
+	$surveyInsertQuery = "INSERT INTO campus.tbl_coodle_surveys $columnsString
+		VALUES $valuesString";
+	$db->db_query($surveyInsertQuery);
+
+	// importing timeslots...
+	$timeslotIds = [];
+	if (count($timeslotsData)) {
+		$timeslotInsertValues = array_map(
+			function ($timeslot) use ($survey) {
+				return "(" . $survey->coodle_id . ", '" . $timeslot["startTime"] . "')";
+			},
+			$timeslotsData
+		);
+		$timeslotInsertValues = implode(", ", $timeslotInsertValues);
+		$timeslotsInsertQuery = "INSERT INTO campus.tbl_coodle_survey_timeslots (survey_id, starts_at) VALUES $timeslotInsertValues";
+		$db->db_query($timeslotsInsertQuery);
+
+		$newTimeslotsQuery = "SELECT * FROM campus.tbl_coodle_survey_timeslots WHERE survey_id = $survey->coodle_id";
+		$newTimeslotsResult = $db->db_query($newTimeslotsQuery);
+		while ($newTimeslot = $db->db_fetch_object($newTimeslotsResult)) {
+			$correspondingOldTimeslotArray = array_values(array_filter(
+				$timeslotsData,
+				function ($oldTimeslot) use ($newTimeslot) {
+					return $oldTimeslot["startTime"] === $newTimeslot->starts_at;
+				}
+			));
+			$correspondingOldTimeslot = count($correspondingOldTimeslotArray) ? $correspondingOldTimeslotArray[0] : null;
+			$timeslotIds[] = [
+				"oldTimeslotId" => isset($correspondingOldTimeslot["oldTimeslotId"]) ? $correspondingOldTimeslot["oldTimeslotId"] : null,
+				"newTimeslotId" => $newTimeslot->id,
+			];
+		}
+	}
+
+	// if there is a selected timeslot, getting its new id and updating survey
+	if ($selectedOldTimeslotId && count($timeslotIds)) {
+		$selectedTimeslotIdArray = array_filter(
+			$timeslotIds,
+			function ($timeslot) use ($selectedOldTimeslotId) {
+				return $timeslot["oldTimeslotId"] === $selectedOldTimeslotId;
+			}
+		);
+		$selectedTimeslotId = count($selectedTimeslotIdArray) ? $selectedTimeslotIdArray[0] : null;
+		$selectedTimeslotNewId = isset($selectedTimeslotId["newTimeslotId"]) ? $selectedTimeslotId["newTimeslotId"] : null;
+		if ($selectedTimeslotNewId) {
+			$surveyUpdateQuery = "UPDATE campus.tbl_coodle_surveys
+				SET selected_timeslot_id = $selectedTimeslotNewId
+				WHERE id = $survey->coodle_id";
+			$db->db_query($surveyUpdateQuery);
+		}
+	}
+
+	// getting old timeslot votes...
+	$votes = [];
+	$oldTimeslotIds = array_map(
+		function ($timeslotId) {
+			return $timeslotId["oldTimeslotId"];
+		},
+		$timeslotIds
+	);
+	$oldTimeslotIds = array_filter(
+		$oldTimeslotIds,
+		function ($oldTimeslotId) {
+			return !!$oldTimeslotId;
+		}
+	);
+	if (count($oldTimeslotIds)) {
+		$oldTimeslotIdsString = "(" . implode(", ", $oldTimeslotIds) . ")";
+		$resourceTimeslotQuery = "SELECT * FROM campus.tbl_coodle_ressource_termin WHERE coodle_termin_id IN $oldTimeslotIdsString";
+		$resourceTimeslotResult = $db->db_query($resourceTimeslotQuery);
+		while ($resourceTimeslot = $db->db_fetch_object($resourceTimeslotResult)) {
+			$timeslotIdArray = array_values(array_filter($timeslotIds, function ($timeslotId) use ($resourceTimeslot) {
+				return $timeslotId["oldTimeslotId"] === $resourceTimeslot->coodle_termin_id;
+			}));
+			$timeslotId = count($timeslotIdArray) ? $timeslotIdArray[0] : null;
+			if ($timeslotId) {
+				$votes[] = [
+					"oldResourceId" => $resourceTimeslot->coodle_ressource_id,
+					"newTimeslotId" => $timeslotId["newTimeslotId"],
+				];
+			}
+		}
+	}
+
+	// getting participant resources...
+	$participantsData = [];
+	$externalParticipantsData = [];
+	$resourcesQuery = "SELECT * FROM campus.tbl_coodle_ressource WHERE coodle_id = $survey->coodle_id";
+	$resourcesResult = $db->db_query($resourcesQuery);
+	while ($resource = $db->db_fetch_object($resourcesResult)) {
+		if ($resource->uid) {
+			$participantData = [
+				"uid" => $resource->uid,
+				"selection" => null,
+			];
+
+			$participantVotes = array_filter(
+				$votes,
+				function ($vote) use ($resource) {
+					return $vote["oldResourceId"] === $resource->coodle_ressource_id;
+				}
+			);
+			if (count($participantVotes)) {
+				$participantData["selection"] = array_map(
+					function ($vote) {
+						return $vote["newTimeslotId"];
+					},
+					$participantVotes
+				);
+			}
+
+			$participantsData[] = $participantData;
+		} else if ($resource->name && $resource->email) {
+			$externalParticipantData = [
+				"name" => $resource->name,
+				"email" => $resource->email,
+				"accessKey" => $resource->zugangscode,
+				"selection" => null,
+			];
+
+			$externalParticipantVotes = array_filter(
+				$votes,
+				function ($vote) use ($resource) {
+					return $vote["oldResourceId"] === $resource->coodle_ressource_id;
+				}
+			);
+			if (count($externalParticipantVotes)) {
+				$externalParticipantData["selection"] = array_map(
+					function ($vote) {
+						return $vote["newTimeslotId"];
+					},
+					$externalParticipantVotes
+				);
+			}
+
+			$externalParticipantsData[] = $externalParticipantData;
+		}
+	}
+
+	if (count($participantsData)) {
+		$participantInsertValues = array_map(
+			function ($participantData) use ($survey) {
+				$formattedSelectionString = $participantData["selection"] !== null ? ("'" . json_encode($participantData["selection"]) . "'") : "NULL";
+				$participantUid = $participantData["uid"];
+				return "($survey->coodle_id, '$participantUid', $formattedSelectionString)";
+			},
+			$participantsData
+		);
+		$participantInsertValues = implode(", ", $participantInsertValues);
+		$participantInsertQuery = "INSERT INTO campus.tbl_coodle_survey_participants (survey_id, participant_uid, selection) VALUES $participantInsertValues";
+		$db->db_query($participantInsertQuery);
+	}
+
+	if (count($externalParticipantsData)) {
+		$externalParticipantInsertValues = array_map(
+			function ($externalParticipantData) use ($survey) {
+				$formattedSelectionString = $externalParticipantData["selection"] !== null ? ("'" . json_encode($externalParticipantData["selection"]) . "'") : "NULL";
+				$externalParticipantName = $externalParticipantData["name"];
+				$externalParticipantEmail = $externalParticipantData["email"];
+				$externalParticipantAccessKey = $externalParticipantData["accessKey"];
+				return "($survey->coodle_id, '$externalParticipantName', '$externalParticipantEmail', '$externalParticipantAccessKey', $formattedSelectionString)";
+			},
+			$externalParticipantsData
+		);
+		$externalParticipantInsertValues = implode(", ", $participantInsertValues);
+		$externalParticipantInsertQuery = "INSERT INTO campus.tbl_coodle_survey_external_participants (survey_id, name, email, access_key, selection) VALUES $externalParticipantInsertValues";
+		$db->db_query($externalParticipantInsertQuery);
+	}
+
+	echo (json_encode($timeslotsData));
+	echo ("<br>");
+	echo (json_encode($participantsData));
+	echo ("<br>");
+	echo (json_encode($externalParticipantsData));
+	echo ("<br>");
+	echo ("-----");
+	echo ("<br>");
+}
+
+function formatDescription($oldDescription)
+{
+	$descriptionWithNewlines = preg_replace("/<br ?\/?>/i", "\n", $oldDescription);
+	$descriptionWithoutHtmlTags = preg_replace("/<.*>/i", "", $descriptionWithNewlines);
+	return trim($descriptionWithoutHtmlTags);
+}
+
+?>
\ No newline at end of file