I am new to working with databases in flutter. I have a data folder with a database.dart in the following form. This is fine for one table and with a few CRUD functions such as newNote or getNotes, but what happens when you have multiple tables and multiple CRUD Functions? Are you supposed to dump them all on this database.dart file making it chaotic? What are better alternatives for organization?
class DBProvider {
DBProvider._();
static final DBProvider db = DBProvider._();
Database _database;
Future<Database> get database async {
if (_database != null) {
return _database;
}
_database = await initDB();
return _database;
}
initDB() async {
Directory documentsDir = await getApplicationDocumentsDirectory();
String path = join(documentsDir.path, 'app.db');
return await openDatabase(path, version: 1, onOpen: (db) async {
}, onCreate: (Database db, int version) async {
// Create the note table
await db.execute('''
CREATE TABLE note(
id INTEGER PRIMARY KEY,
contents TEXT DEFAULT ''
)
''');
});
}
newNote(Note note) async {
final db = await database;
var res = await db.insert('note', note.toJson());
return res;
}
}
Related
Here i want to store the thumbnail to My database which is sqlite, and i am not able to store it. i am able to store it in local directory but. i wana call it from my data model. please help
Here is my Code.
_getThumb(videoPathUrl) async {
var appDocDir = await getApplicationDocumentsDirectory();
final folderPath = appDocDir.path;
print(folderPath);
String thumb = await Thumbnails.getThumbnail(
thumbnailFolder: folderPath,
videoFile: videoPathUrl,
imageType: ThumbFormat.JPEG,
quality: 25,
);
print('thumbnail: $thumb');
return thumb = model.thumbnail;
}
}
I Have Found a Solution "the Problem is not with the plugin or the method it adopts to store the Image" The problem is that it is not clear that how should a Unit8List is to be stored in the database.
In My case. __
I am Using this code to Store the Image.
_getThumb(videoPathUrl) async {
final thumb = await VideoThumbnail.thumbnailData(
video: videoPathUrl,
imageFormat: ImageFormat.JPEG,
maxWidth: 100,
maxHeight: 100,
quality: 75,
);
}
Then I am Using this final thumb to be saved against my VideoModel Variable of thumbnail
_getThumb(videoPathUrl) async {
final thumb = await VideoThumbnail.thumbnailData(
video: videoPathUrl,
imageFormat: ImageFormat.JPEG,
maxWidth: 100,
maxHeight: 100,
quality: 75,
);
print('thumbnail $thumb'); //Add these lines
model.thumbnail = thumb; //Add these Lines
return thumb; //Add these lines
}
And Once i have saved it i can see the print result in my debug console. Once i have that i am sure that it is saved.
Now i have to save it as a Blob in my db not as a String.
and thumbnail should be a Unit8List variable not a String Variable.
See the example
and in database
I am Also adding the full Video Model and DbHelper files for Others to use.
VideoModel.dart
import 'dart:typed_data';
import 'model.dart';
class VideoModel extends Model {
static String table = 'videos';
int id;
String videoName;
String video;
Uint8List thumbnail;
VideoModel({
this.id,
this.videoName,
this.video,
this.thumbnail,
});
static VideoModel fromMap(Map<String, dynamic> map) {
return VideoModel(
id: map["id"],
videoName: map['videoName'].toString(),
video: map['video'],
thumbnail: map['thumbnail'],
);
}
Map<String, dynamic> toMap() {
Map<String, dynamic> map = {
'id': id,
'videoName': videoName,
'video': video,
'thumbnail': thumbnail,
};
if (id != null) {
map['id'] = id;
}
return map;
}
}
DbHelper.dart
abstract class DB {
static Database _db;
static int get _version => 1;
static Future<void> init() async {
if (_db != null) {
return;
}
try {
var databasesPath = await getDatabasesPath();
String _path = p.join(databasesPath, 'video.db');
_db = await openDatabase(_path, version: _version, onCreate: onCreate);
} catch (ex) {
print(ex);
}
}
static void onCreate(Database db, int version) async {
await db.execute(
'CREATE TABLE videos (id INTEGER PRIMARY KEY AUTOINCREMENT, videoName STRING, video STRING, thumbnail BLOB)');
}
static Future<List<Map<String, dynamic>>> query(String table) async =>
_db.query(table);
static Future<int> insert(String table, Model model) async =>
await _db.insert(table, model.toMap());
static Future<int> update(String table, Model model) async => await _db
.update(table, model.toMap(), where: 'id = ?', whereArgs: [model.id]);
static Future<int> delete(String table, Model model) async =>
await _db.delete(table, where: 'id = ?', whereArgs: [model.id]);
static Future<Batch> batch() async => _db.batch();
}
Now when you have done these edits You can just all your image using
Image.memory(add your Image Here);
see example:
I hope that this will help some of you if you need help Let me know. Thanks
I am writing an app to store some events and dates at which events happened (For history students as part of a project). I wish to create an SQLite database, stored in some preferred location in my device. Later I want this database to merge with main database using computer. Here is my database helper class;
class DatabaseHelper {
static final _dbName = 'mainDatabase.db';
static final _dbVersion = 1;
static final _mainTable = 'mainTable';
static final _storyTable = 'storyTable';
static final _topicTable = 'topicTable';
static final columnId = '_id';
static final title = 'title';
static final description = 'description';
static final parentId = 'topic_id';
static final priority = 'priority';
static final iconId = 'iconId';
static final futureImage = 'image';
static final year = 'year';
static final month = 'month';
static final day = 'day';
DatabaseHelper._privateConstructor();
static final DatabaseHelper instance = DatabaseHelper._privateConstructor();
static Database _database;
Future<Database> get database async {
if (_database != null) {
return _database;
}
_database = await _checkPermission();
return _database;
}
var status;
_checkPermission() async {
this.status = await Permission.storage.status;
debugPrint(' storage permission status : ${this.status}');
if (await Permission.storage.request().isGranted) {
_initiateDatabase();
} else if (await Permission.storage.request().isUndetermined) {
debugPrint('Undetermined permission');
} else if (await Permission.storage.request().isDenied) {
debugPrint('Permission denied');
_checkPermission();
} else if (await Permission.storage.request().isPermanentlyDenied) {
debugPrint(' it has been permenantly denied');
}
}
_initiateDatabase() async {
debugPrint(' database initialized');
Directory directory = await getExternalStorageDirectory();
String path = join(directory.path, _dbName);
debugPrint('Path for database: ${path}');
return await openDatabase(path, version: _dbVersion, onCreate: _onCreate);
}
Future _onCreate(Database db, int version) async {
await db.execute('''
CREATE TABLE $_mainTable (
$columnId INTEGER NOT NULL,
$year INTEGER,
$month INTEGER,
$day INTEGER,
$title TEXT NOT NULL,
$description TEXT,
$priority INTEGER,
$parentId INTEGER,
PRIMARY KEY($columnId AUTOINCREMENT)
);
'''); /
Future<int> insertEvent(Map<String, dynamic> row) async {
Database db = await instance.database;
debugPrint(' event : ${row}');
assert(db != null); //Issue!!!!
return await db.insert(_mainTable, row);
}
}
My code may seem messy, because I am not from this background. I apologize for that.
When I tried to add an event I get this error;
I/flutter ( 8090): event id is null
I/flutter ( 8090): storage permission status : PermissionStatus.granted
I/flutter ( 8090): database initialized
I/flutter ( 8090): event : {year: null, month: null, day: null, title: adsfasdf, description: null, priority: 0, topic_id: null}
E/flutter ( 8090): [ERROR:flutter/lib/ui/ui_dart_state.cc(166)] Unhandled Exception: 'package:thisDay/config/databaseHelper.dart': Failed assertion: line 189 pos 12: 'db != null': is not true.
/////////////// some code
E/flutter ( 8090):
I/flutter ( 8090): Path for database: /storage/emulated/0/Android/data/com.example.thisDay/files/mainDatabase.db
What should I do? I am stuck at this point. I have my db file at /storage/emulated/0/Android/data/com.example.thisDay/files/mainDatabase.db . But can't add anything in it.
Any help would be greately appreciated.
Nb:- At first I used getApplicationDirectory instead of External directory. There were no issues. I have to switch because of portability issues
Finally, I fixed my issue by myself. _initializeDatabase() has a return type Future<Database>. So making respective changes on code fixed my issue.
Future<Database> _checkPermission() async {
this.status = await Permission.storage.status;
debugPrint(' storage permission status : ${this.status}');
if (await Permission.storage.request().isGranted) {
return await _initiateDatabase();
} else if (await Permission.storage.request().isUndetermined) {
debugPrint('Undetermined permission');
} else if (await Permission.storage.request().isDenied) {
debugPrint('Permission denied');
_checkPermission();
} else if (await Permission.storage.request().isPermanentlyDenied) {
debugPrint(' it has been permenantly denied');
}
}
Future<Database> _initiateDatabase() async {
debugPrint(' database initialized');
Directory directory = await getExternalStorageDirectory();
String path = join(directory.path, _dbName);
debugPrint('Path for database: ${path}');
return await openDatabase(path, version: _dbVersion, onCreate: _onCreate);
}
for creating a database and table you can refer this code
Database database;
opendatabase() async {
// Delete the database
String databasesPath = await getDatabasesPath();
String path = join(databasesPath, "sample.db");
// await deleteDatabase(path);
database = await openDatabase(path, version: 1,
onCreate: (Database db, int version) async {
// When creating the db, create the table
await db.execute(
'CREATE TABLE tbl_test (id INTEGER PRIMARY KEY, sample TEXT, code TEXT, format TEXT)',
);
});
}
I am trying to make a little project in Flutter where I add some data in a form along with a few images in the sqflite database, but I can't figure out why exactly my code isn't working.
Here is my db_helper class
Future<Database> get db async {
if (_db != null)
return _db;
_db = await initDb();
return _db;
}
//Creating a database with name test.dn in your directory
initDb() async {
io.Directory documentsDirectory = await getApplicationDocumentsDirectory();
String path = join(documentsDirectory.path, "products.db");
var theDb = await openDatabase(path, version: 1, onCreate: _onCreate);
return theDb;
}
// Creating a table name Employee with fields
void _onCreate(Database db, int version) async {
// When creating the db, create the table
await db.execute(
"""CREATE TABLE product(
id INTEGER PRIMARY KEY AUTOINCREMENT,
name TEXT NOT NULL,
brand TEXT NOT NULL,
color TEXT NOT NULL,
size INTEGER NOT NULL,
qty INTEGER NOT NULL)""");
await db.execute(
"""CREATE TABLE image(
id INTEGER PRIMARY KEY AUTOINCREMENT,
path TEXT,
product_id INTEGER,
FOREIGN KEY(product_id) REFERENCES product (id)
ON DELETE NO ACTION ON UPDATE NO ACTION)""");
debugPrint("Created tables");
}
// Get all products
Future<List<Map<String, dynamic>>> getProducts() async {
Database db = this.initDb();
var result = await db.query('product');
return result;
}
// Inser or update image
Future<product_model.Image> insertImage(product_model.Image image) async {
// var count = Sqflite.firstIntValue(await _db.rawQuery("SELECT COUNT(*) FROM image WHERE username = ?", [image.id]));
Database database = await db;
await database.insert("image", image.toMap(), conflictAlgorithm: ConflictAlgorithm.ignore);
// await _db.update("image", image.toMap(), where: "id = ?", whereArgs: [image.id]);
return image;
}
// Inser or update product
Future<product_model.Product> insertProduct(product_model.Product product) async {
// var count = Sqflite.firstIntValue(await _db.rawQuery("SELECT COUNT(*) FROM product WHERE username = ?", [product.id]));
Database database = await db;
await database.insert("product", product.toMap(), conflictAlgorithm: ConflictAlgorithm.ignore);
// await _db.update("product", product.toMap(), where: "id = ?", whereArgs: [product.id]);
return product;
}
And here is where I call the db:
void _saveProductWithPictures() async{
db = DBHelper();
// var db = await dbHelper.initDb();
product = db_elements.Product();
imageModels = List<db_elements.Image>();
int result;
await db.insertProduct(product).whenComplete(() => {
_nameController.clear(),
_brandController.clear(),
_colorController.clear(),
_sizeController.clear(),
_qtyController.clear()
});
if (result != 0) { // Success
_showAlertDialog('Status', 'Note Saved Successfully');
} else { // Failure
_showAlertDialog('Status', 'Problem Saving Note');
}
//save the product
// end save the product
//save the product picture/s
for (var i in _files) imageModels.add(db_elements.Image(path: i.path.toString()));
for (var image in imageModels) await db.insertImage(image).whenComplete(() => {
_files.clear()
});
//end save the product picture/s
}
I tried for weeks to fix this, but still hopeless. I can't save data to the database. Appreciate any kind of help. Thanks in advance
I just added a new "Translations" table to the database init and wrote all the crud methods. Commands db.query and db.insert work just fine, but as tried inside updateVersion() either db.delete or db.update throw the missing plugin error :
ERROR:flutter/lib/ui/ui_dart_state.cc(157)] Unhandled Exception: MissingPluginException(No implementation found for method update on channel com.tekartik.sqflite).
After a while I realised that also older two tables are now throwing the same error on delete and update command. Looks like adding a new table broke it all.. I tried flutter clean but nothing changed, so I uninstalled and reinstalled the app, but I still get same errors. I then commented out new table and reinstalled the app but still get the errors..I also tried invalidating the cache a restart but still the same..
On iPhone dough it does not throw any error..
In iOS CoreData kinda behaves the same when you change something.. but with a fresh app install it all resets.. here it seems that the db is still written on disk..
How do I make sure I erased it? I tried await deleteDatabase(path);.
Any Idea of what's going on?
As always thank you very much for your time and help.
This is the db:
class DBProvider {
//1.Create a private constructor that can be used only inside the class :
DBProvider._();
static final DBProvider db = DBProvider._();
//2.Setup the database
//Next we will create the database object and provide it with a getter
//where we will instantiate the database if it’s not (lazy initialization).
static Database _database;
Future<Database> get database async {
if (_database != null) return _database;
// await Sqflite.devSetDebugModeOn(true);
// if _database is null we instantiate it
_database = await initDB();
return _database;
}
// If there is no object assigned to the database,
// we use the initDB function to create the database.
// In this function, we will get the path for storing the database
// and create the desired tables:
initDB() async {
Directory documentsDirectory = await getApplicationDocumentsDirectory();
String path = join(documentsDirectory.path, "Fixit.db");
//TODO: tried deleting
// await deleteDatabase(path); // still errors
return await openDatabase(path, version: 1, onOpen: (db) {},
onCreate: (Database db, int version) async {
await db.execute("CREATE TABLE Route("
"routeId TEXT,"
"routeName TEXT,"
"routeDistance TEXT,"
"routeDuration TEXT,"
"coordinates TEXT"
")");
await db.execute("CREATE TABLE Alarm("
"alarmId TEXT,"
"alarmName TEXT,"
"enabled BOOL,"
"repeatWeekdays TEXT,"
"time TEXT,"
"sound TEXT,"
"routeName TEXT"
")");
// await db.execute("CREATE TABLE Translations("
// "version TEXT"
// ")");
});
}
}
and these are the CRUD methods:
class DefaultsDbRepository {
var database = DBProvider.db.database;
Future<int> checkVersion() async {
final db = await database;
try {
var res = await db.query('Translations');
assert(res != null);
int version = res != null ? int.parse(res.first['version']) : 0;
print('checkVersion() db version is: $version');
return version;
} catch (err) {
print(err);
}
}
saveVersion({int version}) async {
print('saveVersion() version to save is : $version');
assert(version != null);
final db = await database;
try {
Map<String, dynamic> map = {'version': version};
db.insert("Translations", map);
} catch (e) {
print(e);
}
}
updateVersion({int newVersion, int oldVersion}) async {
print('updateVersion() version to save is : $newVersion');
assert(newVersion != null);
final db = await database;
db.delete("Translations");
try {
// Map<String, dynamic> map = {'version': newVersion};
//
// db.insert("Translations", map);
// db.update("Translations", map); // [ERROR:flutter/lib/ui/ui_dart_state.cc(157)] Unhandled Exception: MissingPluginException(No implementation found for method update on channel com.tekartik.sqflite)
// db.update("Translations", map,
// where: "version = ?", whereArgs: [oldVersion]);
} catch (e) {
print(e);
}
}
}
Finally made it work again. After quite a few, uninstall, flutter clean and reinstalls I saw the problem. I was using ' instead of " in my db methods.
So I changed'ed from:
saveVersion({int version}) async {
print('saveVersion() version to save is : $version');
assert(version != null);
final db = await database;
try {
Map<String, dynamic> map = {'version': version};
db.insert("Translations", map);
} catch (e) {
print(e);
}
}
to:
saveVersion({int version}) async {
print('saveVersion() version to save is : $version');
assert(version != null);
final db = await database;
try {
Map<String, dynamic> map = {"version": version};
db.insert("Translations", map);
} catch (e) {
print(e);
}
}
and all commands are working as expected.
Hope this will be of help to others.
Cheers.
I'm trying to query the last 3 hours of entries from my sqflite database. Here's my current query:
Future<List<Map<String, dynamic>>> queryLastThreeHours() async {
Database db = await instance.database;
return await db.query(table, where: '$columnDate = ?', whereArgs: ['now', '-3 hours']);
}
For more context, here's the complete code for the database_helper.dart:
import 'dart:io';
import 'package:path/path.dart';
import 'package:sqflite/sqflite.dart';
import 'package:path_provider/path_provider.dart';
class DatabaseHelper {
static final _databaseName = "MyDatabase.db";
static final _databaseVersion = 1;
static final table = 'my_table';
static final columnId = '_id';
static final columnName = 'name';
static final columnAge = 'age';
static final columnColour = 'colour';
static final columnDate = 'date';
// make this a singleton class
DatabaseHelper._privateConstructor();
static final DatabaseHelper instance = DatabaseHelper._privateConstructor();
// only have a single app-wide reference to the database
static Database _database;
Future<Database> get database async {
if (_database != null) return _database;
// lazily instantiate the db the first time it is accessed
_database = await _initDatabase();
return _database;
}
// this opens the database (and creates it if it doesn't exist)
_initDatabase() async {
Directory documentsDirectory = await getApplicationDocumentsDirectory();
String path = join(documentsDirectory.path, _databaseName);
return await openDatabase(path,
version: _databaseVersion,
onCreate: _onCreate);
}
// SQL code to create the database table
Future _onCreate(Database db, int version) async {
await db.execute('''
CREATE TABLE $table (
$columnId INTEGER PRIMARY KEY,
$columnName TEXT NOT NULL,
$columnAge INTEGER NOT NULL,
$columnColour TEXT NOT NULL,
$columnDate INTEGER NOT NULL
)
''');
}
// Helper methods
// Inserts a row in the database where each key in the Map is a column name
// and the value is the column value. The return value is the id of the
// inserted row.
Future<int> insert(Map<String, dynamic> row) async {
Database db = await instance.database;
return await db.insert(table, row);
}
// All of the rows are returned as a list of maps, where each map is
// a key-value list of columns.
Future<List<Map<String, dynamic>>> queryAllRows() async {
Database db = await instance.database;
return await db.query(table);
}
// All of the methods (insert, query, update, delete) can also be done using
// raw SQL commands. This method uses a raw query to give the row count.
Future<int> queryRowCount() async {
Database db = await instance.database;
return Sqflite.firstIntValue(await db.rawQuery('SELECT COUNT(*) FROM $table'));
}
// We are assuming here that the id column in the map is set. The other
// column values will be used to update the row.
Future<int> update(Map<String, dynamic> row) async {
Database db = await instance.database;
int id = row[columnId];
return await db.update(table, row, where: '$columnId = ?', whereArgs: [id]);
}
// Deletes the row specified by the id. The number of affected rows is
// returned. This should be 1 as long as the row exists.
Future<int> delete(int id) async {
Database db = await instance.database;
return await db.delete(table, where: '$columnId = ?', whereArgs: [id]);
}
Future<List<Map<String, dynamic>>> queryOmnivore() async {
Database db = await instance.database;
return await db.query(table, where: '$columnColour = ?', whereArgs: ['Omnivore']);
}
Future<List<Map<String, dynamic>>> queryLastThreeHours() async {
Database db = await instance.database;
return await db.query(table, where: '$columnDate = ?', whereArgs: ['now', '-3 hours']);
}
}
Any help would be greatly appreciated. I've tried to work it out using Sqlite SELECT * for Last 7 days and How to get Last 3 hours data from SQLite, but still haven't figured it out.
Thank you very much in advance!
Jason