Flutter：如何将动态列表插入到 sqflite

Question

我有一个 flutter 应用程序想在初始化数据库时将数据列表添加到 sqlite 数据库，我对模型类型有疑问。我有这个数据模型：

import 'dart:convert';

List<Clubs> clubsFromMap(String str) =>
    List<Clubs>.from(json.decode(str).map((x) => Clubs.fromMap(x)));

String clubsToMap(List<Clubs> data) =>
    json.encode(List<dynamic>.from(data.map((x) => x.toMap())));

class Clubs {
  Clubs({
    this.id,
    this.club,
    this.leagueId,
    this.price,
    this.surname,
    this.leagueName,
    this.counter,
    this.selected,
  });

  int id;
  String club;
  int leagueId;
  String price;
  String surname;
  String leagueName;
  int counter;
  String selected;

  factory Clubs.fromMap(Map<String, dynamic> json) => Clubs(
        id: json["id"],
        club: json["club"],
        leagueId: json["league_id"],
        price: json["price"],
        surname: json["surname"],
        leagueName: json["league_name"],
        counter: json["counter"],
        selected: json["selected"],
      );

  Map<String, dynamic> toMap() => {
        "id": id,
        "club": club,
        "league_id": leagueId,
        "price": price,
        "surname": surname,
        "league_name": leagueName,
        "counter": counter,
        "selected": selected,
      };
}

我有该模型的数据列表：

var clubs = [
    {
      "id": 1,
      "club": "Manchester City",
      "league_id": 1,
      "price": "10.00",
      "surname": "MCY",
      "league_name": "Premier League",
      "counter": 1,
      "selected": "No"
    },
  ..................etc
]

不，我想将这个初始数据添加到 sqflite 数据库，我创建了它：

import 'package:sqflite/sqflite.dart';
class DataBaseService {
  static final DataBaseService _instance = DataBaseService.internal();
  factory DataBaseService() => _instance;
  DataBaseService.internal();

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

Future<Database> intializeDataBase() async {
    var dir = await getDatabasesPath();
    var path = dir + "clubs.db";
    var database =
        await openDatabase(path, version: 1, onCreate: (db, version) {
      db.execute('''
      create table $clubsTableName(
        columnId integer primary key,
        $columnClub text not null,
        $columnLeaueId integer,
        $columnPrice double,
        $columnSurname text not null,
        $columnLeagueName text,
        $columnCounter integer.
        $columnSelected text,
      )
      ''');
db.insert(clubsTableName,clubs.toMap());

它说 toMap() 没有定义，如果我把它改成 clubsFromMap(clubs) 而不是 clubs.toMap() 它说：The argument type 'List<Clubs>' can't be assigned to the parameter type 'Map<String, Object>'.dart(argument_type_not_assignable)

我该如何解决这个问题？

Answer 1

我把列表格式改成这样解决了：

var clubs = {"data":{
    {
      "id": 1,
      "club": "Manchester City",
      "league_id": 1,
      "price": "10.00",
      "surname": "MCY",
      "league_name": "Premier League",
      "counter": 1,
      "selected": "No"
    },
  ..................etc}
}

Flutter：如何将动态列表插入到 sqflite

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