SQFlite 未找到现有 Table

Question

我正在尝试查询我数据库中 Table 名称为 'links' 的所有数据，但我总是收到此错误：

W/e.dsa_regelwik( 4691): Accessing hidden method Lsun/misc/Unsafe;->getUnsafe()Lsun/misc/Unsafe; (greylist,core-platform-api, linking, allowed)
W/e.dsa_regelwik( 4691): Accessing hidden method Lsun/misc/Unsafe;->objectFieldOffset(Ljava/lang/reflect/Field;)J (greylist,core-platform-api, linking, allowed)
W/e.dsa_regelwik( 4691): Accessing hidden method Lsun/misc/Unsafe;->compareAndSwapObject(Ljava/lang/Object;JLjava/lang/Object;Ljava/lang/Object;)Z (greylist, linking, allowed)
W/e.dsa_regelwik( 4691): Accessing hidden method Lsun/misc/Unsafe;->putObject(Ljava/lang/Object;JLjava/lang/Object;)V (greylist, linking, allowed)
E/SQLiteLog( 4691): (1) no such table: links

这是我的助手class，具有查询功能：

import 'dart:io';
import 'package:flutter/services.dart';
import 'package:path/path.dart';
import 'package:path_provider/path_provider.dart';
import 'package:sqflite/sqflite.dart';

import 'model.dart';

class DatabaseHelper {
  DatabaseHelper._privateConstructor();

  static final DatabaseHelper instance = DatabaseHelper._privateConstructor();

  static Database? _database;

  Future<Database> get database async => _database ??= await _initDatabase();

  Future<Database> _initDatabase() async {
    Directory documentsDirectory = await getApplicationDocumentsDirectory();
    String path = join(documentsDirectory.path, 'DSA_Database.db');
    return await openDatabase(
      path,
      version: 1,
      onCreate: _onCreate,
    );
  }

  Future _onCreate(Database db, int version) async {
    var databasesPath = await getDatabasesPath();
    var path = join(databasesPath, 'DSA_Database.db');
    await deleteDatabase(path);

    ByteData data = await rootBundle.load(join('assets', 'DSA_Database.db'));
    List<int> bytes = data.buffer.asUint8List(data.offsetInBytes, data.lengthInBytes);
    await new File(path).writeAsBytes(bytes, flush: true);
  }

  Future<List<Titles>> getTitles() async {
    Database db = await instance.database;
    var titles = await db.rawQuery('SELECT * FROM links');
    List<Titles> titlesList =
        titles.isNotEmpty
            ? titles.map((e) => Titles.fromMap(e)).toList()
            : [];
    return titlesList;
  }
}

从 5 天以来我一直在尝试修复该错误，但我找不到该问题的任何解决方案。

Answer 1

您似乎正试图在打开数据库时删除它（即在 onCreate 期间），这将不起作用，因为此时数据库已经打开。在调用 openDatabase.

之前，您应该在 _onCreate 中移动您当前正在做的事情

有关如何打开资产数据库的示例，请参阅 https://github.com/tekartik/sqflite/blob/master/sqflite/doc/opening_asset_db.md。

SQFlite 未找到现有 Table

SQFlite does not find existing Table

dart

flutter

sqflite