无法从Flutter中的资产读取SQL文件

Question

I'm trying to load prepopulated data into my flutter application. I've created 'assets' folder in the root of my project & put 'mydb.sql' file into that folder.

Added that file reference in pubspec.yaml

assets:
  - assets/mydb.sql

Below is my code of DBHandler.dart file to access database

  static Database _db;
  String dbName = "mydb.sql";

  Future<Database> get db async {
    if (_db != null) return _db;
    _db = await initDb();
    return _db;
  }

  initDb() async {
    var databasesPath = await getDatabasesPath();
    var path = join(databasesPath, dbName);
    var exists = await databaseExists(path);
    if (!exists) {
      // Should happen only the first time you launch your application
      print("Creating new copy from asset");

      // Make sure the parent directory exists
      try {
        await io.Directory(dirname(path)).create(recursive: true);
      } catch (_) {}

      // Copy from asset
      ByteData data = await rootBundle.load(join('assets',dbName));
      List<int> bytes =
          data.buffer.asUint8List(data.offsetInBytes, data.lengthInBytes);

      // Write and flush the bytes written
      await io.File(path).writeAsBytes(bytes, flush: true);
    } else {
      print("Opening existing database");
    }
    return await openDatabase(path);
  }

the error I'm getting is

I/flutter (16900): Creating new copy from asset
E/flutter (16900): [ERROR:flutter/lib/ui/ui_dart_state.cc(148)] Unhandled Exception: Unable to load asset: assets/mydb.sql
E/flutter (16900): #0      PlatformAssetBundle.load (package:flutter/src/services/asset_bundle.dart:221:7)
E/flutter (16900): <asynchronous suspension>
E/flutter (16900): #1      DBHandler.initDb (package:MyApp/db/DBHandler.dart:36:40)

which is below given line from code.

ByteData data = await rootBundle.load(join('assets',dbName));

Answer 1

There were 2 issues in my code. Writing this to help others doing the same mistake.

1. Indentation in pubspec.yaml
I was doing a major silly mistake. I was just looking at

assets:
  - assets/mydb.sql

my pubspec file was something was like this

  flutter:

  # The following line ensures that the Material Icons font is
  # included with your application, so that you can use the icons in
  # the material Icons class.
  uses-material-design: true

  # To add assets to your application, add an assets section, like this:
  assets:
    - assets/mydb.sqlite

I didn't notice that my 'flutter:' & 'assets:' was on the same level. so I changed it to

flutter:

  # The following line ensures that the Material Icons font is
  # included with your application, so that you can use the icons in
  # the material Icons class.
  uses-material-design: true

  # To add assets to your application, add an assets section, like this:
    assets:
      - assets/mydb.sqlite

Notice the indentation (2 spaces before 'assets:')

2. sql file is not db So, I got this issue after solving the first one. I got mydb.sql is not a database. So I exported my database as '.sqlite' file from Sqlite Database Browser. & updated my pubspec & DBHandler file.

Thanks to @Shababb Karim's comment for pointing out pubspec.yaml issue.