플러터SQLFLITE 업데이트 포함

import 'dart:async';
import 'package:flutter_sqlite_demo/models/model.dart';
import 'package:sqflite/sqflite.dart';

abstract class DB {

    static Database _db;

    static int get _version => 1;

    static Future<void> init() async {

        if (_db != null) { return; }

        try {
            String _path = await getDatabasesPath() + 'example';
            _db = await openDatabase(_path, version: _version, onCreate: onCreate, onUpdate:_onUpdate);
        }
        catch(ex) { 
            print(ex);
        }
    }

    static void onCreate(Database db, int version) async =>
        await db.execute('CREATE TABLE todo_items (id INTEGER PRIMARY KEY NOT NULL, task STRING, complete BOOLEAN)');
	
    // 버전을 올린 뒤에 사용하는 코드, 버전을 올리면 새로 만들때도 memo TEXT를 넣어줘야 함
    static void _onUpgrade(Database db, int oldVersion, int newVersion) {
    if (oldVersion < newVersion) {
      db.execute("ALTER TABLE todo_items ADD COLUMN memo TEXT;");
      }
    }
    
    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]);