I am trying to store the image in SQFLite database as string. While setting up the DBHelper class, I am getting the said error.
Here is the code of model.dart and dbhelper.dart

class Photo {
  int? id;
  String? photoName;

  Photo({this.id, this.photoName});

  Map<String, dynamic> toMap() {
    var map = <String, dynamic>{
      'id': id,
      'photoName': photoName,
    };
    return map;
  }

  Photo.fromMap(Map<String, dynamic> map) {
    id = map['id'];
    photoName = map['photoName'];
  }
}

import 'package:path_provider/path_provider.dart';
import 'package:sqflite/sqflite.dart';
import 'package:path/path.dart';
import 'model.dart';
import 'dart:io' as io;
import 'dart:async';

class DBHelper {
  static Database? _db;
  static const String ID = 'id';
  static const String NAME = 'photoName';
  static const String TABLE = 'PhotosTable';
  static const String DB_NAME = 'photos.db';

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

  initDb() async {
    io.Directory documentsDirectory = await getApplicationDocumentsDirectory();
    String path = join(documentsDirectory.path, DB_NAME);
    var db = await openDatabase(path, version: 1, onCreate: _onCreate);
    return db;
  }

  _onCreate(Database db, int version) async {
    await db.execute("CREATE TABLE $TABLE ($ID INTEGER, $NAME TEXT)");
  }

  Future<Photo> save(Photo photo) async {
    var dbClient = await db;
    photo.id = await dbClient!.insert(TABLE, photo.toMap());
    return photo;
  }

  Future<List<Photo>> getPhotos() async {
    var dbClient = await db;
    List<Map> maps = await dbClient!.query(TABLE, columns: [ID, NAME]);
    List<Photo> photos = [];
    if (maps.length > 0) {
      for (int i = 0; i < maps.length; i  ) {
        photos.add(Photo.fromMap(maps[i]));     // ==> Here, at maps[i], it shows the error
      }
    }
    return photos;
  }

  Future close() async {
    var dbClient = await db;
    dbClient!.close();
  }
}

How can I solve this ?

CodePudding user response：

Change your Photo model to Map<dynamic, dynamic>. The reason for this is that the db is returning a Map<dynamic, dynamic>.

class Photo {
  int? id;
  String? photoName;

  Photo({this.id, this.photoName});

  Map<dynamic, dynamic> toMap() {
    var map = <String, dynamic>{
      'id': id,
      'photoName': photoName,
    };
    return map;
  }

  Photo.fromMap(Map<dynamic, dynamic> map) {
    id = map['id'];
    photoName = map['photoName'];
  }
}