Add player choice to episode editor.

db.py

@@ -1,5 +1,7 @@
 import sqlite3
 import logging as log
+from typing import Sequence
+
 from flask import g
 
 import models
@@ -187,6 +189,12 @@ def load_episodes(season_id: int = None):
     return sql, args
 
 
+def save_episode_players(episode_id: int, player_ids: Sequence[int]):
+    sql = "insert into episode_player values (?, ?)"
+    args = [(episode_id, i) for i in player_ids]
+    return sql, args
+
+
 def save_episode(episode: models.Episode):
     if not episode.id:
         sql = "insert into episode values (?, ?, ?, ?, ?, ?, ?)"