88 lines
3 KiB
Dart
88 lines
3 KiB
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 = "Orma.db";
|
||
|
|
static final _databaseVersion = 1;
|
||
|
|
|
||
|
|
static final table = 'synced_photos';
|
||
|
|
|
||
|
|
static final columnId = 'photo_id';
|
||
|
|
static final columnLocalUrl = 'local_url';
|
||
|
|
static final columnTimestamp = 'timestamp';
|
||
|
|
|
||
|
|
// 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,
|
||
|
|
$columnLocalUrl TEXT NOT NULL,
|
||
|
|
$columnTimestamp INTEGER NOT NULL
|
||
|
|
)
|
||
|
|
''');
|
||
|
|
}
|
||
|
|
|
||
|
|
// Helper methods
|
||
|
|
|
||
|
|
// Inserts a row in the database where each key in the Map is a column name
|
||
|
|
// and the value is the column value. The return value is the id of the
|
||
|
|
// inserted row.
|
||
|
|
Future<int> insert(Map<String, dynamic> row) async {
|
||
|
|
Database db = await instance.database;
|
||
|
|
return await db.insert(table, row);
|
||
|
|
}
|
||
|
|
|
||
|
|
// All of the rows are returned as a list of maps, where each map is
|
||
|
|
// a key-value list of columns.
|
||
|
|
Future<List<Map<String, dynamic>>> queryAllRows() async {
|
||
|
|
Database db = await instance.database;
|
||
|
|
return await db.query(table);
|
||
|
|
}
|
||
|
|
|
||
|
|
// All of the methods (insert, query, update, delete) can also be done using
|
||
|
|
// raw SQL commands. This method uses a raw query to give the row count.
|
||
|
|
Future<int> queryLastTimestamp() async {
|
||
|
|
Database db = await instance.database;
|
||
|
|
return Sqflite.firstIntValue(await db.rawQuery('SELECT MAX($columnTimestamp) 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]);
|
||
|
|
}
|
||
|
|
}
|