schema: Playlist tags may be null, indicating "match nothing"

This is intended for partially-entered playlist data where tags have not been specified yet.

playlist_manager/playlist_manager/main.py

@@ -110,7 +110,7 @@ class PlaylistManager(object):
 				[tag.lower() for tag in row.tags],
 				row.first_event_id,
 				row.last_event_id,
-			) for row in query(conn, "SELECT playlist_id, tags, first_event_id, last_event_id FROM playlists")
+			) for row in query(conn, "SELECT playlist_id, tags, first_event_id, last_event_id FROM playlists WHERE tags IS NOT NULL")
 		}
 		self.dbmanager.put_conn(conn)
 		duplicates = set(playlists) & set(self.static_playlists)

postgres/setup.sh

@@ -142,11 +142,12 @@ CREATE TABLE editors (
 );
 
 -- Playlists are communicated to playlist manager via this table.
--- Sheetsync will wipe and re-populate this table periodically to match what is in the sheet
 CREATE TABLE playlists (
 	playlist_id TEXT PRIMARY KEY,
 	name TEXT NOT NULL,
-	tags TEXT[] NOT NULL,
+	-- When tags is NULL, it indicates tags have not been set and so the playlist should
+	-- match nothing. Conversely, when tags is empty, it indicates the playlist should match everything.
+	tags TEXT[],
 	first_event_id UUID REFERENCES events(id) ON DELETE SET NULL,
 	last_event_id UUID REFERENCES events(id) ON DELETE SET NULL,
 	show_in_description BOOLEAN NOT NULL

thrimshim/thrimshim/main.py

@@ -303,7 +303,7 @@ def update_row(ident, editor=None):
 		playlists = database.query(conn, """ 
 			SELECT playlist_id, name, tags
 			FROM playlists
-			WHERE show_in_description
+			WHERE show_in_description AND tags IS NOT NULL
 		""")
 		# Filter for matching playlists for this video
 		playlists = [