データベースが読み込めない

SqliteException(11): while executing, database disk image is malformed, database disk image is malformed (code 11)
Causing statement: CREATE TABLE IF NOT EXISTS "words" ("id" INTEGER NOT NULL, "sort" TEXT NOT NULL, "name" TEXT NOT NULL, "english" TEXT NOT NULL, "rank" INTEGER NOT NULL, "read" TEXT NOT NULL, "start" TEXT NOT NULL, "end" TEXT NOT NULL, "nerve" TEXT NOT NULL, "medulla" TEXT NOT NULL, "action" TEXT NOT NULL, "sub" TEXT NOT NULL, "comment" TEXT NOT NULL, PRIMARY KEY ("name"));, parameters:

void _getAllWords() async{
    _wordList = await database.allWords;
    setState(() {});
  }

//一番基本の土台画面。

import 'dart:io';

import 'package:flutter/material.dart';
import 'package:flutter/services.dart';
import 'package:kinnikutango/db/database.dart';
import 'screens/app.dart';
import 'package:path/path.dart';//手入力付けたし
import 'package:path_provider/path_provider.dart';//手入力付けたし

late MyDatabase database;

void main() async{
  WidgetsFlutterBinding.ensureInitialized();
  var dbPath = await getDbPath();
  database = MyDatabase(dbPath: dbPath);

  runApp(MyApp());
}

Future<String> getDbPath() async{
  var dbDir = await getApplicationDocumentsDirectory();
  var dbPath = join(dbDir.path, "word.db");
  
  if(FileSystemEntity.typeSync(dbPath) == FileSystemEntityType.notFound){
    ByteData byteData = await rootBundle.load("assets/db/word.db");
    List<int> bytes = byteData.buffer.asUint8List(byteData.offsetInBytes, byteData.lengthInBytes);
    await File(dbPath).writeAsBytes(bytes);
  }
  return dbPath;
}

class MyApp extends StatelessWidget {
  const MyApp({Key? key}) : super(key: key);

  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      title: "筋肉単語", //TODO  後でタイトル変更する
      home: AppScreen(),
      theme: ThemeData(
        fontFamily: "NotoSansJapanese",//フォント変更
        appBarTheme: AppBarTheme(
          backgroundColor: Color(0xFF96BBFF),
          centerTitle: true,
        ),
      ),
      debugShowCheckedModeBanner: false,//デバッグの右上のリボンみたいなのを消す
    );
  }
}

import 'package:flutter/material.dart';
import '../db/database.dart';
import '../main.dart';
import 'edit_screen.dart';

class WordListScreen extends StatefulWidget {
  const WordListScreen({Key? key}) : super(key: key);

  @override
  State<WordListScreen> createState() => _WordListScreenState();
}

class _WordListScreenState extends State<WordListScreen> {

  List<Word> _wordList = [];

  @override
  void initState() {
    super.initState();
    _getAllWords();
  }

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(
        title: const Text('単語一覧'),
        actions: [
          IconButton(
            icon: Icon(Icons.add),
            onPressed: () => _addNewWord(),
            tooltip: "新しい単語の登録", //長押しすると説明文を出す
          ),
        ],
      ),
      body: _wordListWidget(),
    );
  }

  _addNewWord() {
    Navigator.pushReplacement(
        context, MaterialPageRoute(builder: (context) => EditScreen()));
  }

  void _getAllWords() async{
    _wordList = await database.allWords;
    setState(() {});
  }

  Widget _wordListWidget() {
    return ListView.builder(
      itemCount: _wordList.length,
        itemBuilder: (context, int position) => _wordItem(position));
  }

  Widget _wordItem(int position) {
    return Card(
      child: ListTile(
        title: Text(
          "${_wordList[position].name}"
        ),
        subtitle: Text(
          "${_wordList[position].read}"
        ),
      ),
    );
  }
}

import 'dart:io';

import 'package:drift/drift.dart';
import 'package:drift/native.dart';
import 'package:path_provider/path_provider.dart';
import 'package:sqlite3_flutter_libs/sqlite3_flutter_libs.dart';
import 'package:sqlite3/sqlite3.dart';

part 'database.g.dart';

class Words extends Table {
  IntColumn get id => integer()();

  TextColumn get sort => text().nullable()();

  TextColumn get name => text()();

  TextColumn get english => text().nullable()();

  IntColumn get rank => integer().nullable()();

  TextColumn get read => text().nullable()();

  TextColumn get start => text().nullable()();

  TextColumn get end => text().nullable()();

  TextColumn get nerve => text().nullable()();

  TextColumn get medulla => text().nullable()();

  TextColumn get action => text().nullable()();

  TextColumn get sub => text().nullable()();

  TextColumn get comment => text().nullable()();

  @override
  Set<Column> get primaryKey => {name};
}

@DriftDatabase(tables: [Words])
class MyDatabase extends _$MyDatabase {
  final String dbPath;

  MyDatabase({required this.dbPath})
      : super(_openConnection(dbPath)); //null許容のエラーが出たから、「required」追加した。

  @override
  int get schemaVersion => 1;

  //Creates
  Future addWord(Word word) => into(words).insert(word);

  //Read
  Future<List<Word>> get allWords => select(words).get();

  //Update
  Future updateWord(Word word) => update(words).replace(word);

  //Delete
  Future deleteWord(Word word) =>
      (delete(words)..where((t) => t.name.equals(word.name))).go();
}

LazyDatabase _openConnection(String dbPath) {
  // the LazyDatabase util lets us find the right location for the file async.
  return LazyDatabase(() async {
    // put the database file, called db.sqlite here, into the documents folder
    // for your app.
    //final dbFolder = await getApplicationDocumentsDirectory();//本当にいらんのか不明。
    final file = File(dbPath);

    // Also work around limitations on old Android versions
    if (Platform.isAndroid) {
      await applyWorkaroundToOpenSqlite3OnOldAndroidVersions();
    }

    // Make sqlite3 pick a more suitable location for temporary files - the
    // one from the system may be inaccessible due to sandboxing.
    final cachebase = (await getTemporaryDirectory()).path;
    // We can't access /tmp on Android, which sqlite3 would try by default.
    // Explicitly tell it about the correct temporary directory.
    sqlite3.tempDirectory = cachebase;

    return NativeDatabase.createInBackground(file);
  });
}