Fix migration

api/migration.sql

 
 UPDATE data.job SET cause_job_id = NULL, cause_user_id = NULL WHERE id >= 0;
 
+DELETE FROM lecture_daily_watch_stats;
+DELETE FROM lecture_watch_stats;
+DELETE FROM publish_medium_segment_watch_stats;
+DELETE FROM publish_medium_watch_client_stats;
+DELETE FROM publish_medium_watch_log_entry;
+DELETE FROM publish_medium_watcher;
+
 DELETE FROM data.featured WHERE id >= 0;
 DELETE FROM data.announcement WHERE id >= 0;
 DELETE FROM data.changelog_entry WHERE id >= 0;
@@ -214,7 +221,17 @@ INSERT INTO data.lecture (id, deleted, visible, course_id, title, speaker, locat
     disable_automatic_media_process_scheduler)
 SELECT id, deleted, visible, course_id, title, speaker, place, "time", duration, comment,
     norecording, live, internal,
-    (SELECT MIN(time_created) FROM old_data.videos_data AS vid WHERE vid.lecture_id = old_lec.id AND vid.visible AND NOT vid.deleted),  -- publish_time
+    (
+        SELECT MIN(
+            CASE
+                -- There are some "0" timestamps
+                WHEN time_created > '1900-01-01 00:00:00'::timestamp THEN time_created
+                ELSE file_modified
+            END
+        )
+        FROM old_data.videos_data AS vid
+        WHERE vid.lecture_id = old_lec.id AND vid.visible AND NOT vid.deleted
+    ),  -- publish_time
     'inherit', False, False, NULL, NULL,  -- view_perm (filled below)
     False  -- disable_automatic_media_process_scheduler (Already disabled by course)
 FROM old_data.lectures_data AS old_lec