Database: Fix worksByComposer

While the previous code was indeed valid SQL is wasn't the best way to
do this. Also, only works with parts where included in the result set.
This is fixed now. Some optimization may still be neccessary.

lib/database.dart

@@ -35,14 +35,6 @@ class Database extends _$Database {
         await customStatement('PRAGMA foreign_keys = ON');
       });
 
-  // TODO: Remove this once https://github.com/simolus3/moor/issues/453 is fixed.
-  Selectable<Work> worksByComposer(int id) {
-    return customSelectQuery(
-        'SELECT DISTINCT A.* FROM works A, works B ON A.id = B.part_of WHERE A.composer = :id OR B.composer = :id',
-        variables: [Variable.withInt(id)],
-        readsFrom: {works}).map(_rowToWork);
-  }
-
   Future<void> updatePerson(Person person) async {
     await into(persons).insert(person, orReplace: true);
   }
@@ -85,7 +77,9 @@ class Database extends _$Database {
   Future<void> updateRecording(
       Recording recording, List<Performance> perfs) async {
     await transaction(() async {
-      await (delete(performances)..where((p) => p.recording.equals(recording.id))).go();
+      await (delete(performances)
+            ..where((p) => p.recording.equals(recording.id)))
+          .go();
       await into(recordings).insert(recording, orReplace: true);
       for (final perf in perfs) {
         await into(performances).insert(perf);

lib/database.moor

@@ -63,10 +63,10 @@ SELECT * FROM works WHERE id = :id LIMIT 1;
 workParts:
 SELECT * FROM works WHERE part_of = :id ORDER BY part_index;
 
--- TODO: Uncomment this once https://github.com/simolus3/moor/issues/453 is fixed.
--- worksByComposer(:id AS INTEGER):
--- SELECT DISTINCT A.* FROM works A, works B ON A.id = B.part_of
---     WHERE A.composer = :id OR B.composer = :id;
+-- TODO: Maybe optimize.
+worksByComposer:
+SELECT DISTINCT A.* FROM works A LEFT JOIN works B ON A.id = B.part_of
+    WHERE A.part_of IS NULL AND A.composer = :id OR B.composer = :id;
 
 composersByWork:
 SELECT DISTINCT persons.* FROM persons