Redo how works are stored

Before works where stored using a complicated tree structure where each
part references its parent. Now it's a flat structure that keeps track
of the relations using a new field named part_level. The corresponding
query was simplified accordingly. Also, the updateWork function was
rewritten.
This commit is contained in:
Elias Projahn 2020-03-21 14:34:45 +01:00
parent b15591b388
commit 4b178752b9
2 changed files with 44 additions and 21 deletions

View file

@ -7,6 +7,16 @@ part 'database.g.dart';
final _random = Random(DateTime.now().millisecondsSinceEpoch);
int generateId() => _random.nextInt(0xFFFFFFFF);
class WorkModel {
final Work work;
final List<int> instrumentIds;
WorkModel({
@required this.work,
@required this.instrumentIds,
});
}
@UseMoor(
include: {
'database.moor',
@ -19,6 +29,14 @@ class Database extends _$Database {
@override
int get schemaVersion => 1;
// TODO: Remove this once https://github.com/simolus3/moor/issues/453 is fixed.
Selectable<Work> worksByComposer(int id) {
return customSelectQuery(
'SELECT DISTINCT A.* FROM works A, works B ON A.id = B.part_of WHERE A.composer = :id OR B.composer = :id',
variables: [Variable.withInt(id)],
readsFrom: {works}).map(_rowToWork);
}
Future<void> updatePerson(Person person) async {
await into(persons).insert(person);
}
@ -27,19 +45,26 @@ class Database extends _$Database {
await into(instruments).insert(instrument);
}
Future<void> updateWork(Work work, List<int> instrumentIds) async {
Future<void> updateWork(WorkModel model, List<WorkModel> parts) async {
await transaction(() async {
await into(works).insert(work);
final workId = model.work.id;
await (delete(works)..where((w) => w.id.equals(workId))).go();
await (delete(works)..where((w) => w.partOf.equals(workId))).go();
await (delete(instrumentations)..where((i) => i.work.equals(work.id)))
.go();
Future<void> insertWork(WorkModel model) async {
await into(works).insert(model.work);
await batch((b) => b.insertAll(
instrumentations,
model.instrumentIds
.map((id) =>
Instrumentation(work: model.work.id, instrument: id))
.toList()));
}
await into(instrumentations).insertAll(instrumentIds
.map((id) => Instrumentation(
work: work.id,
instrument: id,
))
.toList());
await insertWork(model);
for (final part in parts) {
await insertWork(part);
}
});
}
}

View file

@ -14,7 +14,8 @@ CREATE TABLE works (
composer INTEGER REFERENCES persons(id),
title TEXT NOT NULL,
part_of INTEGER REFERENCES works(id) ON DELETE CASCADE,
part_index INTEGER
part_index INTEGER,
part_level INTEGER
);
CREATE TABLE instrumentations (
@ -37,16 +38,13 @@ SELECT * FROM instruments WHERE id = :id LIMIT 1;
workById:
SELECT * FROM works WHERE id = :id LIMIT 1;
worksByComposer:
WITH RECURSIVE work_parts(id, part_of) AS (
SELECT id, part_of FROM works WHERE composer = :composerId
UNION ALL
SELECT works.id, works.part_of FROM works
JOIN work_parts ON works.id = work_parts.part_of
)
SELECT works.* FROM works
JOIN work_parts ON works.id = work_parts.id
WHERE work_parts.part_of IS NULL;
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;
instrumentsByWork:
SELECT instruments.* FROM instrumentations