由于 Flutter 中的模型文件，无法在 sqlite 数据库中插入值
Can't insert values in sqlite database because of the model file in Flutter
我正在尝试解析下面的 API 响应并将响应保存在 sqlite 数据库中。但是在保存过程中收到此错误消息。我认为这是因为我无法正确创建此模型文件。无法弄清楚如何在“Map toJson()”部分中实现 2 class。
错误：
Invalid argument [{id: 1, name: İstanbul Ayasofya Müzesi, session_time: 12, distId: AYS, photo: https://api.thevoiceofmuseums.com/storage/contents/museums/1.jpeg, address: null, lat: null, long: null, sectionId: AYS01, email: null, updated_at: 2019-07-20T13:42:53.000, created_at: 2019-06-20T02:27:21.000}, {id: 2, name: İstanbul Topkapı Sarayı Müzesi, session_time: 12, distId: TPK01, photo: https://api.thevoiceofmuseums.com/storage/contents/museums/2.jpeg, address: null, lat: null, long: null, sectionId: TPK01, email: null, updated_at: 2019-07-20T13:44:12.000, created_at: 2019-06-21T14:11:43.000}, {id: 3, name: İstanbul Topkapı Sarayı - Harem Dairesi, session_time: 12, distId: TPK02, photo: https://api.thevoiceofmuseums.com/storage/contents/museums/3.jpeg, address: null, lat: null, long: null, sectionId: TPK02, email: null, updated_at: 2019-07-20T13:44:22.000, created_at: 2019-06-21T14:12:48.000}, {id: 4, name: İstanbul Topkapı Sarayı Müzesi ve Harem Dairesi, session_time: 12, di
E/flutter ( 7093): [ERROR:flutter/lib/ui/ui_dart_state.cc(186)] Unhandled Exception: DatabaseException(java.util.HashMap cannot be cast to java.lang.Integer) sql 'INSERT INTO museums_list.db (data) VALUES (?)' args
Table查看截图：
这是我的端点响应：
{
"data": [
{
"id": 1,
"name": "İstanbul Ayasofya Müzesi",
"session_time": 12,
"distId": "AYS",
"photo": "https://api.thevoiceofmuseums.com/storage/contents/museums/1.jpeg",
"address": "null",
"lat": "null",
"long": "null",
"sectionId": "AYS01",
"email": "null",
"updated_at": "2019-07-20 13:42:53",
"created_at": "2019-06-20 02:27:21"
},
{
"id": 2,
"name": "İstanbul Topkapı Sarayı Müzesi",
"session_time": 12,
"distId": "TPK01",
"photo": "https://api.thevoiceofmuseums.com/storage/contents/museums/2.jpeg",
"address": "null",
"lat": "null",
"long": "null",
"sectionId": "TPK01",
"email": "null",
"updated_at": "2019-07-20 13:44:12",
"created_at": "2019-06-21 14:11:43"
},
{
"id": 3,
"name": "İstanbul Topkapı Sarayı - Harem Dairesi",
"session_time": 12,
"distId": "TPK02",
"photo": "https://api.thevoiceofmuseums.com/storage/contents/museums/3.jpeg",
"address": "null",
"lat": "null",
"long": "null",
"sectionId": "TPK02",
"email": "null",
"updated_at": "2019-07-20 13:44:22",
"created_at": "2019-06-21 14:12:48"
}
]
}
模型文件：
final String tableMuseums = 'MuseumsListTable';
// column names for database
class MuseumsFields {
static const String MUSEUM_ID = 'id';
static const String MUSEUM_NAME = 'name';
static const String SESSION_TIME = 'session_time';
static const String MUSEUM_DIST_ID = 'distId';
static const String MUSEUM_PHOTO = 'photo';
static const String MUSEUM_ADDRESS = 'address';
static const String LAT = 'lat';
static const String LONG = 'long';
static const String MUSEUM_SECTION_ID = 'sectionId';
static const String EMAIL = 'email';
static const String UPDATED_AT = 'updated_at';
static const String CREATED_AT = 'created_at';
}
class MuseumsList {
List<Data>? data;
MuseumsList({this.data});
MuseumsList.fromJson(Map<String, dynamic> json) {
if (json['data'] != null) {
data = <Data>[];
json['data'].forEach((v) {
data!.add(new Data.fromJson(v));
});
}
}
Map<String, dynamic> toJson() {
print("TOJSON");
final Map<String, dynamic> data = new Map<String, dynamic>();
if (this.data != null) {
data['data'] = this.data!.map((v) => v.toJson()).toList();
}
return data;
}
}
class Data {
int? id;
String? name;
int? sessionTime;
String? distId;
String? photo;
String? address;
String? lat;
String? long;
String? sectionId;
String? email;
DateTime? updatedAt;
DateTime? createdAt;
Data({
this.id,
this.name,
this.sessionTime,
this.distId,
this.photo,
this.address,
this.lat,
this.long,
this.sectionId,
this.email,
this.updatedAt,
this.createdAt,
});
Data.fromJson(Map<String, dynamic> json) {
id = json['id'];
name = json['name'];
sessionTime = json['session_time'];
distId = json['distId'];
photo = json['photo'];
address = json['address'];
lat = json['lat'];
long = json['long'];
sectionId = json['sectionId'];
email = json['email'];
updatedAt = DateTime.parse(json["updated_at"]);
createdAt = DateTime.parse(json["created_at"]);
}
Map<String, Object?> toJson() => {
MuseumsFields.MUSEUM_ID: id,
MuseumsFields.MUSEUM_NAME: name,
MuseumsFields.SESSION_TIME: sessionTime,
MuseumsFields.MUSEUM_DIST_ID: distId,
MuseumsFields.MUSEUM_PHOTO: photo,
MuseumsFields.MUSEUM_ADDRESS: address,
MuseumsFields.LAT: lat,
MuseumsFields.LONG: long,
MuseumsFields.MUSEUM_SECTION_ID: sectionId,
MuseumsFields.EMAIL: email,
MuseumsFields.UPDATED_AT: updatedAt!.toIso8601String(),
MuseumsFields.CREATED_AT: createdAt!.toIso8601String(),
};
}
数据库提供程序文件：
import 'dart:io';
import 'package:path/path.dart';
import 'package:the_vom/models/museums_list_model.dart';
import 'package:path_provider/path_provider.dart';
import 'package:sqflite/sqflite.dart';
class DBProvider {
static final DBProvider instance = DBProvider._init();
static Database? _database;
DBProvider._init();
Future<Database?> get database async {
if (_database != null) return _database!;
_database = await _initDB('museums.db');
return _database;
}
Future<Database> _initDB(String filePath) async {
// final dbPath = await getDatabasesPath();
Directory documentsDirectory = await getApplicationDocumentsDirectory();
String path = join(documentsDirectory.path, filePath);
print('database location: $path');
return await openDatabase(path, version: 1, onCreate: _createDB);
}
Future _createDB(Database db, int version) async {
final idType = 'INTEGER PRIMARY KEY';
final textType = 'TEXT';
final intType = 'INTEGER';
await db.execute('''
CREATE TABLE $tableMuseums (
${MuseumsFields.MUSEUM_ID} $idType,
${MuseumsFields.MUSEUM_NAME} $textType,
${MuseumsFields.SESSION_TIME} $intType,
${MuseumsFields.MUSEUM_DIST_ID} $textType,
${MuseumsFields.MUSEUM_PHOTO} $textType,
${MuseumsFields.MUSEUM_ADDRESS} $textType,
${MuseumsFields.LAT} $textType,
${MuseumsFields.LONG} $textType,
${MuseumsFields.MUSEUM_SECTION_ID} $textType,
${MuseumsFields.EMAIL} $textType,
${MuseumsFields.UPDATED_AT} $textType,
${MuseumsFields.CREATED_AT} $textType
)
''');
print("database table is created.");
}
Future<MuseumsList> create(MuseumsList museum) async {
print("inside of create function in db_provider.dart");
final db = await instance.database;
final json = museum.toJson();
print("+++++++++++");
print(json.values);
print("+++++++++++");
// // COLUMN NAMES
// final columns =
// '${MuseumsFields.MUSEUM_ID}, ${MuseumsFields.MUSEUM_NAME}, ${MuseumsFields.SESSION_TIME}, ${MuseumsFields.MUSEUM_DIST_ID}, ${MuseumsFields.MUSEUM_PHOTO}, ${MuseumsFields.MUSEUM_ADDRESS}, ${MuseumsFields.LAT}, ${MuseumsFields.LONG}, ${MuseumsFields.MUSEUM_SECTION_ID}, ${MuseumsFields.EMAIL}, ${MuseumsFields.UPDATED_AT}, ${MuseumsFields.CREATED_AT}';
// // ROWS
// final values =
// '${json[MuseumsFields.MUSEUM_ID]}, ${json[MuseumsFields.MUSEUM_NAME]}, ${json[MuseumsFields.SESSION_TIME]}, ${json[MuseumsFields.MUSEUM_DIST_ID]}, ${json[MuseumsFields.MUSEUM_PHOTO]}, ${json[MuseumsFields.MUSEUM_ADDRESS]}, ${json[MuseumsFields.LAT]}, ${json[MuseumsFields.LONG]}, ${json[MuseumsFields.MUSEUM_SECTION_ID]}, ${json[MuseumsFields.EMAIL]}, ${json[MuseumsFields.UPDATED_AT]}, ${json[MuseumsFields.CREATED_AT]}';
//
// final y = await db!
// .rawInsert('INSERT INTO $tableMuseums ($columns) VALUES ($values)');
final x =
await db!.insert(tableMuseums, museum.toJson()); //convert to a map.
print("museums are saved in the database.");
return museum;
}
Future close() async {
final db = await instance.database;
db!.close();
}
}
服务文件：我将解码后的 response.body 传递给数据库提供商，如下所示。
class MuseumsService {
Future getMuseums() async {
print("Future getMuseums");
try {
// headers of the post request
final _headers = {
//todo bearer token, remove the hardcoded one.
'Authorization': _hardCodedBearerToken,
'Content-Type': 'application/x-www-form-urlencoded',
};
// body of the post request
// final _body = '';
// sending post request
http.Response response = await http.post(
loginAPIURL,
headers: _headers,
// body: _body,
);
print("getMuseums Request Sent!");
//get response from endpoint
if (response.statusCode == 200) {
print('$loginAPIURL Endpoint Response: response.body');
print(response.body);
MuseumsList museums =
await MuseumsList.fromJson(jsonDecode(response.body));
// print(museums.data![0].name);
DBProvider.instance.create(museums); //-> ****
}
} catch (e) {
print(e);
return throw Exception("MUSEUMSLIST ALINAMADI");
}
}
}
您正在尝试插入 MuseumsList.toJson 而不是 Data.toJson
的结果
试试这样的东西：
Future<MuseumsList> create(MuseumsList museums) async {
print("inside of create function in db_provider.dart");
final db = await instance.database;
// {'data': [...]}
final jsons = museums.toJson();
if (jsons['data'] != null) {
batch = db!.batch();
jsons['data'].forEach((museum) {
batch.insert(tableMuseums, museum);
});
await batch.commit();
}
print("museums are saved in the database.");
return museums;
}
我正在尝试解析下面的 API 响应并将响应保存在 sqlite 数据库中。但是在保存过程中收到此错误消息。我认为这是因为我无法正确创建此模型文件。无法弄清楚如何在“Map
错误：
Invalid argument [{id: 1, name: İstanbul Ayasofya Müzesi, session_time: 12, distId: AYS, photo: https://api.thevoiceofmuseums.com/storage/contents/museums/1.jpeg, address: null, lat: null, long: null, sectionId: AYS01, email: null, updated_at: 2019-07-20T13:42:53.000, created_at: 2019-06-20T02:27:21.000}, {id: 2, name: İstanbul Topkapı Sarayı Müzesi, session_time: 12, distId: TPK01, photo: https://api.thevoiceofmuseums.com/storage/contents/museums/2.jpeg, address: null, lat: null, long: null, sectionId: TPK01, email: null, updated_at: 2019-07-20T13:44:12.000, created_at: 2019-06-21T14:11:43.000}, {id: 3, name: İstanbul Topkapı Sarayı - Harem Dairesi, session_time: 12, distId: TPK02, photo: https://api.thevoiceofmuseums.com/storage/contents/museums/3.jpeg, address: null, lat: null, long: null, sectionId: TPK02, email: null, updated_at: 2019-07-20T13:44:22.000, created_at: 2019-06-21T14:12:48.000}, {id: 4, name: İstanbul Topkapı Sarayı Müzesi ve Harem Dairesi, session_time: 12, di
E/flutter ( 7093): [ERROR:flutter/lib/ui/ui_dart_state.cc(186)] Unhandled Exception: DatabaseException(java.util.HashMap cannot be cast to java.lang.Integer) sql 'INSERT INTO museums_list.db (data) VALUES (?)' args
Table查看截图：
这是我的端点响应：
{
"data": [
{
"id": 1,
"name": "İstanbul Ayasofya Müzesi",
"session_time": 12,
"distId": "AYS",
"photo": "https://api.thevoiceofmuseums.com/storage/contents/museums/1.jpeg",
"address": "null",
"lat": "null",
"long": "null",
"sectionId": "AYS01",
"email": "null",
"updated_at": "2019-07-20 13:42:53",
"created_at": "2019-06-20 02:27:21"
},
{
"id": 2,
"name": "İstanbul Topkapı Sarayı Müzesi",
"session_time": 12,
"distId": "TPK01",
"photo": "https://api.thevoiceofmuseums.com/storage/contents/museums/2.jpeg",
"address": "null",
"lat": "null",
"long": "null",
"sectionId": "TPK01",
"email": "null",
"updated_at": "2019-07-20 13:44:12",
"created_at": "2019-06-21 14:11:43"
},
{
"id": 3,
"name": "İstanbul Topkapı Sarayı - Harem Dairesi",
"session_time": 12,
"distId": "TPK02",
"photo": "https://api.thevoiceofmuseums.com/storage/contents/museums/3.jpeg",
"address": "null",
"lat": "null",
"long": "null",
"sectionId": "TPK02",
"email": "null",
"updated_at": "2019-07-20 13:44:22",
"created_at": "2019-06-21 14:12:48"
}
]
}
模型文件：
final String tableMuseums = 'MuseumsListTable';
// column names for database
class MuseumsFields {
static const String MUSEUM_ID = 'id';
static const String MUSEUM_NAME = 'name';
static const String SESSION_TIME = 'session_time';
static const String MUSEUM_DIST_ID = 'distId';
static const String MUSEUM_PHOTO = 'photo';
static const String MUSEUM_ADDRESS = 'address';
static const String LAT = 'lat';
static const String LONG = 'long';
static const String MUSEUM_SECTION_ID = 'sectionId';
static const String EMAIL = 'email';
static const String UPDATED_AT = 'updated_at';
static const String CREATED_AT = 'created_at';
}
class MuseumsList {
List<Data>? data;
MuseumsList({this.data});
MuseumsList.fromJson(Map<String, dynamic> json) {
if (json['data'] != null) {
data = <Data>[];
json['data'].forEach((v) {
data!.add(new Data.fromJson(v));
});
}
}
Map<String, dynamic> toJson() {
print("TOJSON");
final Map<String, dynamic> data = new Map<String, dynamic>();
if (this.data != null) {
data['data'] = this.data!.map((v) => v.toJson()).toList();
}
return data;
}
}
class Data {
int? id;
String? name;
int? sessionTime;
String? distId;
String? photo;
String? address;
String? lat;
String? long;
String? sectionId;
String? email;
DateTime? updatedAt;
DateTime? createdAt;
Data({
this.id,
this.name,
this.sessionTime,
this.distId,
this.photo,
this.address,
this.lat,
this.long,
this.sectionId,
this.email,
this.updatedAt,
this.createdAt,
});
Data.fromJson(Map<String, dynamic> json) {
id = json['id'];
name = json['name'];
sessionTime = json['session_time'];
distId = json['distId'];
photo = json['photo'];
address = json['address'];
lat = json['lat'];
long = json['long'];
sectionId = json['sectionId'];
email = json['email'];
updatedAt = DateTime.parse(json["updated_at"]);
createdAt = DateTime.parse(json["created_at"]);
}
Map<String, Object?> toJson() => {
MuseumsFields.MUSEUM_ID: id,
MuseumsFields.MUSEUM_NAME: name,
MuseumsFields.SESSION_TIME: sessionTime,
MuseumsFields.MUSEUM_DIST_ID: distId,
MuseumsFields.MUSEUM_PHOTO: photo,
MuseumsFields.MUSEUM_ADDRESS: address,
MuseumsFields.LAT: lat,
MuseumsFields.LONG: long,
MuseumsFields.MUSEUM_SECTION_ID: sectionId,
MuseumsFields.EMAIL: email,
MuseumsFields.UPDATED_AT: updatedAt!.toIso8601String(),
MuseumsFields.CREATED_AT: createdAt!.toIso8601String(),
};
}
数据库提供程序文件：
import 'dart:io';
import 'package:path/path.dart';
import 'package:the_vom/models/museums_list_model.dart';
import 'package:path_provider/path_provider.dart';
import 'package:sqflite/sqflite.dart';
class DBProvider {
static final DBProvider instance = DBProvider._init();
static Database? _database;
DBProvider._init();
Future<Database?> get database async {
if (_database != null) return _database!;
_database = await _initDB('museums.db');
return _database;
}
Future<Database> _initDB(String filePath) async {
// final dbPath = await getDatabasesPath();
Directory documentsDirectory = await getApplicationDocumentsDirectory();
String path = join(documentsDirectory.path, filePath);
print('database location: $path');
return await openDatabase(path, version: 1, onCreate: _createDB);
}
Future _createDB(Database db, int version) async {
final idType = 'INTEGER PRIMARY KEY';
final textType = 'TEXT';
final intType = 'INTEGER';
await db.execute('''
CREATE TABLE $tableMuseums (
${MuseumsFields.MUSEUM_ID} $idType,
${MuseumsFields.MUSEUM_NAME} $textType,
${MuseumsFields.SESSION_TIME} $intType,
${MuseumsFields.MUSEUM_DIST_ID} $textType,
${MuseumsFields.MUSEUM_PHOTO} $textType,
${MuseumsFields.MUSEUM_ADDRESS} $textType,
${MuseumsFields.LAT} $textType,
${MuseumsFields.LONG} $textType,
${MuseumsFields.MUSEUM_SECTION_ID} $textType,
${MuseumsFields.EMAIL} $textType,
${MuseumsFields.UPDATED_AT} $textType,
${MuseumsFields.CREATED_AT} $textType
)
''');
print("database table is created.");
}
Future<MuseumsList> create(MuseumsList museum) async {
print("inside of create function in db_provider.dart");
final db = await instance.database;
final json = museum.toJson();
print("+++++++++++");
print(json.values);
print("+++++++++++");
// // COLUMN NAMES
// final columns =
// '${MuseumsFields.MUSEUM_ID}, ${MuseumsFields.MUSEUM_NAME}, ${MuseumsFields.SESSION_TIME}, ${MuseumsFields.MUSEUM_DIST_ID}, ${MuseumsFields.MUSEUM_PHOTO}, ${MuseumsFields.MUSEUM_ADDRESS}, ${MuseumsFields.LAT}, ${MuseumsFields.LONG}, ${MuseumsFields.MUSEUM_SECTION_ID}, ${MuseumsFields.EMAIL}, ${MuseumsFields.UPDATED_AT}, ${MuseumsFields.CREATED_AT}';
// // ROWS
// final values =
// '${json[MuseumsFields.MUSEUM_ID]}, ${json[MuseumsFields.MUSEUM_NAME]}, ${json[MuseumsFields.SESSION_TIME]}, ${json[MuseumsFields.MUSEUM_DIST_ID]}, ${json[MuseumsFields.MUSEUM_PHOTO]}, ${json[MuseumsFields.MUSEUM_ADDRESS]}, ${json[MuseumsFields.LAT]}, ${json[MuseumsFields.LONG]}, ${json[MuseumsFields.MUSEUM_SECTION_ID]}, ${json[MuseumsFields.EMAIL]}, ${json[MuseumsFields.UPDATED_AT]}, ${json[MuseumsFields.CREATED_AT]}';
//
// final y = await db!
// .rawInsert('INSERT INTO $tableMuseums ($columns) VALUES ($values)');
final x =
await db!.insert(tableMuseums, museum.toJson()); //convert to a map.
print("museums are saved in the database.");
return museum;
}
Future close() async {
final db = await instance.database;
db!.close();
}
}
服务文件：我将解码后的 response.body 传递给数据库提供商，如下所示。
class MuseumsService {
Future getMuseums() async {
print("Future getMuseums");
try {
// headers of the post request
final _headers = {
//todo bearer token, remove the hardcoded one.
'Authorization': _hardCodedBearerToken,
'Content-Type': 'application/x-www-form-urlencoded',
};
// body of the post request
// final _body = '';
// sending post request
http.Response response = await http.post(
loginAPIURL,
headers: _headers,
// body: _body,
);
print("getMuseums Request Sent!");
//get response from endpoint
if (response.statusCode == 200) {
print('$loginAPIURL Endpoint Response: response.body');
print(response.body);
MuseumsList museums =
await MuseumsList.fromJson(jsonDecode(response.body));
// print(museums.data![0].name);
DBProvider.instance.create(museums); //-> ****
}
} catch (e) {
print(e);
return throw Exception("MUSEUMSLIST ALINAMADI");
}
}
}
您正在尝试插入 MuseumsList.toJson 而不是 Data.toJson
的结果试试这样的东西：
Future<MuseumsList> create(MuseumsList museums) async {
print("inside of create function in db_provider.dart");
final db = await instance.database;
// {'data': [...]}
final jsons = museums.toJson();
if (jsons['data'] != null) {
batch = db!.batch();
jsons['data'].forEach((museum) {
batch.insert(tableMuseums, museum);
});
await batch.commit();
}
print("museums are saved in the database.");
return museums;
}