在Flutter中使用SQFlite将本地存储的DB导出为可读文件

dependencies:
  sqflite: any

import 'package:sqflite/sqflite.dart';
import 'package:path/path.dart';

class DatabaseHelper {
  static final DatabaseHelper _instance = DatabaseHelper.internal();
  factory DatabaseHelper() => _instance;

  static Database? _database;

  Future<Database?> get database async {
    if (_database != null) {
      return _database;
    }

    _database = await initDatabase();
    return _database;
  }

  DatabaseHelper.internal();

  Future<Database> initDatabase() async {
    String databasesPath = await getDatabasesPath();
    String path = join(databasesPath, 'mydatabase.db');

    return await openDatabase(
      path,
      version: 1,
      onCreate: (Database db, int version) async {
        await db.execute('CREATE TABLE mytable (id INTEGER PRIMARY KEY, name TEXT)');
      },
    );
  }

  Future<List<Map<String, dynamic>>> exportDatabase() async {
    Database? db = await database;
    return await db!.query('mytable');
  }
}

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

Future<void> exportDB() async {
  List<Map<String, dynamic>> data = await DatabaseHelper().exportDatabase();
  
  // 将数据库数据导出为文件
  String content = '';
  data.forEach((row) {
    content += '${row['id']},${row['name']}\n';
  });

  // 获取应用程序的文档目录
  Directory? appDocumentsDirectory = await getApplicationDocumentsDirectory();
  String filePath = '${appDocumentsDirectory!.path}/exported_db.csv';

  // 将内容写入文件
  File file = File(filePath);
  await file.writeAsString(content);

  // 在控制台打印文件路径
  print('导出的文件路径：$filePath');
}