How to save image as blob in sqlite in flutter - flutter

Question

I'm using Flutter, I need to save image in SQLite as BLOB, then display it in my page.
I did it as String and it works fine but not image with 1.5 MB size, the app get unhanded exception, I tried to do it as blob but I could not find any tutorial anywhere.
My model:
import 'package:flutter/services.dart';
const String tablePersonal = 'personal_info';
class PersonalFields {
static final List<String> values = [
id,
name,
logo,
];
static const String id = '_id';
static const String name = 'name';
static const String logo = 'logo';
}
class PersonalInfoModel {
int? id;
final String name;
final Uint8List? logo;
PersonalInfoModel({
this.id,
required this.name,
this.logo,
});
PersonalInfoModel copy({
int? id,
String? name,
Uint8List? logo,
}) =>
PersonalInfoModel(
id: id ?? this.id,
name: name ?? this.name,
logo: logo ?? this.logo,
);
static PersonalInfoModel fromJson(Map<String, Object?> json) =>
PersonalInfoModel(
id: json[PersonalFields.id] as int?,
name: json[PersonalFields.name] as String,
logo: json[PersonalFields.logo] as Uint8List?,
);
Map<String, dynamic> toJson() => {
PersonalFields.id: id,
PersonalFields.name: name,
PersonalFields.logo: logo,
};
}
SQL Helper: after create the table I just make insert null record to save the id = 1 so that I will just update the record. That is means the table will only get one record.
batch.execute('''
CREATE TABLE IF NOT EXISTS $tablePersonal
(
${PersonalFields.id} $idType,
${PersonalFields.name} $textType,
${PersonalFields.logo} $blobType
)
''');
batch.execute('''
INSERT INTO $tablePersonal
(
${PersonalFields.name}
)
VALUES
(
''
)
''');
//read personal info
Future<List<PersonalInfoModel>> getPesonalInfo() async {
var db = await instanace.database;
final result = await db.query(tablePersonal);
return result.map((json) => PersonalInfoModel.fromJson(json)).toList();
}
Future<int> updatePersonalInfo(PersonalInfoModel personalInfoModel) async {
final db = await instanace.database;
return db.update(
tablePersonal,
personalInfoModel.toJson(),
where: '${PersonalFields.id} = ?',
whereArgs: [personalInfoModel.id],
);
}
My Page:
import 'dart:convert';
import 'dart:io';
import 'package:flutter/material.dart';
import 'package:flutter/services.dart';
import 'package:image_picker/image_picker.dart';
import 'package:ledger/database/sql_helper.dart';
import 'package:ledger/l10n/app_local.dart';
import 'package:ledger/models/personal_info_model.dart';
class PersonalInfoPage extends StatefulWidget {
const PersonalInfoPage({Key? key}) : super(key: key);
#override
State<PersonalInfoPage> createState() => _PersonalInfoPageState();
}
class _PersonalInfoPageState extends State<PersonalInfoPage> {
final _formKey = GlobalKey<FormState>();
final TextEditingController _nameController = TextEditingController();
double boxWidth = 10;
double boxHieght = 10;
XFile? xImage;
var bytes;
final ImagePicker _picker = ImagePicker();
late List<PersonalInfoModel> personalList;
late PersonalInfoModel existPersonal;
bool isLoading = true;
#override
void initState() {
super.initState();
getPersonalInfo();
}
Future pickImage() async {
try {
xImage = await _picker.pickImage(source: ImageSource.gallery);
if (xImage == null) return;
final imagePath = File(xImage!.path);
bytes = imagePath;
setState(() {});
} on PlatformException catch (e) {
print('Failed to pick image: $e');
}
}
Future getPersonalInfo() async {
final data = await SQLHelper.instanace.getPesonalInfo();
setState(() {
personalList = data;
getData();
isLoading = false;
});
}
getData() {
existPersonal = personalList.firstWhere((element) => element.id == 1);
_nameController.text = existPersonal.name;
bytes = existPersonal.logo;
}
Future updatePersonalInfo(PersonalInfoModel personalInfoModel) async {
await SQLHelper.instanace.updatePersonalInfo(personalInfoModel);
getPersonalInfo();
}
#override
Widget build(BuildContext context) {
return Scaffold(
appBar: AppBar(
title: Text(AppLocal.loc.personal_info),
actions: [
IconButton(
onPressed: () {
PersonalInfoModel personalInfoModel = PersonalInfoModel(
id: 1,
name: _nameController.text,
logo: bytes);
updatePersonalInfo(personalInfoModel);
},
icon: const Icon(Icons.save_as_outlined),
),
],
),
body: isLoading
? const Center(child: CircularProgressIndicator())
: SingleChildScrollView(
child: Column(
children: [
Padding(
padding: const EdgeInsets.symmetric(horizontal: 5.0),
child: Form(
key: _formKey,
child: Column(
children: [
SizedBox(height: boxHieght),
TextFormField(
controller: _nameController,
decoration: InputDecoration(
filled: true,
labelText: AppLocal.loc.name,
border: const OutlineInputBorder(
borderRadius: BorderRadius.all(
Radius.circular(5.0),
),
),
),
),
],
),
),
),
Row(
mainAxisAlignment: MainAxisAlignment.center,
children: [
TextButton(
onPressed: () {
print('xxxxxx');
pickImage();
},
child: Text('from Gallary'),
),
],
),
Container(
color: Colors.grey.shade100,
height: 150,
width: 150,
child: bytes != null
? Image.memory(bytes)
: Image.asset('assets/logo.png'),
),
],
),
),
);
}
}

Answer 1

Here is how you can convert it into a blob and save it to SQLite
Future pickImage(ImageSource source) async {
try {
final image = await ImagePicker.pickImage(source: source);
final imagePath = File(image.path);
List<int> bytes = await image.readAsBytes();
String base64 = base64Encode(bytes);// here it is. Save it to sqflite
} on PlatformException catch (e) {
print(e);
}
}
for getting from SQLite
String blobImageFromSqflite; //get from sqflite
Uint8List _bytesImage = Base64Decoder().convert(blobImageFromSqflite);
to display it;
Image.memory(
_bytesImage,
);