Fix foreign key

Foreign keys need to be re-enable with each session

Otherwise e.g. `ON DELETE CASCADE` for the automatic index removal does not work.

Revert explicit delete introduced in 9bcc24d

CHANGELOG.md

@@ -1,3 +1,8 @@
+## 1.4.6
+
+* Re-enable foreign key constraint for every session
+  * Clean up unused indices which were not automatically removed before (but will be going forward)
+
 ## 1.4.5
 
 * try/catch with `ROLLBACK` in case a transaction fails, so as to not leave the database in a locked state

example/pubspec.lock

@@ -105,7 +105,7 @@ packages:
       path: ".."
       relative: true
     source: path
-    version: "1.4.5"
+    version: "1.4.6"
   leak_tracker:
     dependency: transitive
     description:

lib/src/index_entity_store.dart

@@ -268,6 +268,7 @@ class IndexedEntityStore<T, K> {
       _entityInsertStatement.execute(
         [_entityKey, _connector.getPrimaryKey(e), _connector.serialize(e)],
       );
+      _assertNoMoreIndexEntries(_connector.getPrimaryKey(e));
 
       _updateIndexInternal(e);
 
@@ -311,19 +312,12 @@ class IndexedEntityStore<T, K> {
     _handleUpdate(keys);
   }
 
-  late final _deleteIndexStatement = _database.prepare(
-    'DELETE FROM `index` WHERE `type` = ? AND `entity` = ?',
-    persistent: true,
-  );
-
   late final _insertIndexStatement = _database.prepare(
     'INSERT INTO `index` (`type`, `entity`, `field`, `value`) VALUES (?, ?, ?, ?)',
     persistent: true,
   );
 
   void _updateIndexInternal(T e) {
-    _deleteIndexStatement.execute([_entityKey, _connector.getPrimaryKey(e)]);
-
     for (final indexColumn in _indexColumns._indexColumns.values) {
       _insertIndexStatement.execute(
         [
@@ -376,11 +370,22 @@ class IndexedEntityStore<T, K> {
         'DELETE FROM `entity` WHERE `type` = ? AND `key` = ?',
         [_entityKey, key],
       );
+
+      _assertNoMoreIndexEntries(key);
     }
 
     _handleUpdate(keys);
   }
 
+  void _assertNoMoreIndexEntries(K key) {
+    assert(
+      _database.select(
+        'SELECT * FROM `index` WHERE `type` = ? and `entity` = ?',
+        [_entityKey, key],
+      ).isEmpty,
+    );
+  }
+
   void _ensureIndexIsUpToDate() {
     final currentlyIndexedFields = _database
         .select(

lib/src/indexed_entity_database.dart

@@ -14,13 +14,26 @@ class IndexedEntityDabase {
 
       _initialDBSetup();
       _v2Migration();
+      _v3Migration();
     } else if (_dbVersion == 1) {
       debugPrint('Migrating DB to v2');
 
       _v2Migration();
+      _v3Migration();
+    } else if (_dbVersion == 2) {
+      _v3Migration();
     }
 
-    assert(_dbVersion == 2);
+    assert(_dbVersion == 3);
+
+    // Foreign keys need to be re-enable on every open (session)
+    // https://www.sqlite.org/foreignkeys.html#fk_enable
+    _database.execute('PRAGMA foreign_keys = ON');
+
+    // Ensure that the library used actually supports foreign keys
+    assert(
+      _database.select('PRAGMA foreign_keys').first.values.first as int == 1,
+    );
   }
 
   void _initialDBSetup() {
@@ -68,6 +81,20 @@ class IndexedEntityDabase {
     );
   }
 
+  void _v3Migration() {
+    final res = _database.select(
+      'DELETE FROM `index` WHERE NOT EXISTS (SELECT COUNT(*) FROM `entity` WHERE `entity`.`type` = type AND `entity`.`key` = entity) RETURNING `index`.`type`',
+    );
+    if (res.isNotEmpty) {
+      debugPrint('Cleaned up ${res.length} unused indices');
+    }
+
+    _database.execute(
+      'UPDATE `metadata` SET `value` = ? WHERE `key` = ?',
+      [3, 'version'],
+    );
+  }
+
   factory IndexedEntityDabase.open(String path) {
     return IndexedEntityDabase._(path);
   }

pubspec.yaml

@@ -1,6 +1,6 @@
 name: indexed_entity_store
 description: A fast, simple, and synchronous entity store for Flutter applications.
-version: 1.4.5
+version: 1.4.6
 repository: https://github.com/LunaONE/indexed_entity_store
 
 environment:

test/indexed_entity_store_test.dart

@@ -606,6 +606,66 @@ void main() {
     },
   );
 
+  test(
+    'Foreign key constraint persists across sessions',
+    () async {
+      final path =
+          '/tmp/index_entity_store_test_${FlutterTimeline.now}.sqlite3';
+
+      final db = IndexedEntityDabase.open(path);
+
+      final indexedEntityConnector =
+          IndexedEntityConnector<_AllSupportedIndexTypes, String, String>(
+        entityKey: 'indexed_entity',
+        getPrimaryKey: (e) => e.string,
+        getIndices: (index) {
+          index((e) => e.string, as: 'string');
+        },
+        serialize: (f) => jsonEncode(f.toJSON()),
+        deserialize: (s) => _AllSupportedIndexTypes.fromJSON(
+          jsonDecode(s) as Map<String, dynamic>,
+        ),
+      );
+
+      final store = db.entityStore(indexedEntityConnector);
+
+      expect(store.getAllOnce(), isEmpty);
+
+      final e = _AllSupportedIndexTypes.defaultIfNull(string: 'default');
+
+      store.insert(e);
+
+      db.dispose();
+
+      // now open again, ensuring foreign keys are still on and thus `index`
+      // will be cleaned up with entity removals & overwrites
+
+      // delete & insert
+      {
+        final db = IndexedEntityDabase.open(path);
+
+        final store = db.entityStore(indexedEntityConnector);
+
+        store.delete('default');
+        expect(store.getAllOnce(), isEmpty);
+        store.insert(e);
+
+        db.dispose();
+      }
+
+      // second insert (overwrite)
+      {
+        final db = IndexedEntityDabase.open(path);
+
+        final store = db.entityStore(indexedEntityConnector);
+
+        store.insert(e);
+
+        db.dispose();
+      }
+    },
+  );
+
   test('Query operations', () async {
     final path = '/tmp/index_entity_store_test_${FlutterTimeline.now}.sqlite3';