Fix duplicate artist links

INSERT OR REPLACE does not work when null values are provided as part of the unique index

jellyfin_kodi/objects/kodi/kodi.py

@@ -147,8 +147,8 @@ def add_thumbnail(person_id, person, person_type):
                 bulk_updates.setdefault(sql, []).append((person_id,) + args)
 
             elif person['Type'] == 'Artist':
-                sql = QU.update_link.replace("{LinkType}", 'actor_link')
-                bulk_updates.setdefault(sql, []).append((person_id,) + args)
+                sql = QU.insert_link_if_not_exists.replace("{LinkType}", 'actor_link')
+                bulk_updates.setdefault(sql, []).append((person_id,) + args + (person_id,) + args)
 
             add_thumbnail(person_id, person, person['Type'])
 

jellyfin_kodi/objects/kodi/queries.py

@@ -395,6 +395,13 @@
 INSERT OR REPLACE INTO      {LinkType}(actor_id, media_id, media_type)
 VALUES                      (?, ?, ?)
 """
+# update_link does not work for actor_link as not all values from unique index are provided
+# Resulting in duplicates
+insert_link_if_not_exists = """
+INSERT INTO                 {LinkType}(actor_id, media_id, media_type)
+SELECT ?, ?, ? 
+WHERE NOT EXISTS(SELECT 1 FROM {LinkType} WHERE actor_id = ? AND media_id = ? AND media_type = ?)
+"""
 update_movie = """
 UPDATE      movie
 SET         c00 = ?, c01 = ?, c02 = ?, c03 = ?, c04 = ?, c05 = ?, c06 = ?,