Flutter异步SQLite数据库操作插件sqlite3_async的使用

sqlite3_async 是一个为 sqlite3 插件提供异步操作功能的包。它支持诸如打开数据库、执行SQL命令、配置用户版本和获取最后插入行ID等异步操作。

特性

• 异步打开Sqlite数据库
• 异步执行SQL命令
• 配置数据库用户版本
• 获取最后插入行的ID

开始使用

首先，你需要在项目中添加 sqlite3_async 和 sqlite3_flutter_libs 依赖：

flutter pub add sqlite3_async
flutter pub add sqlite3_flutter_libs

对于其他平台的支持，请参阅 sqlite3 文档。

使用示例

下面是一个完整的Flutter应用示例，展示了如何使用 sqlite3_async 来进行基本的数据库操作，如创建表、插入数据以及查询数据。

示例代码

import 'package:flutter/material.dart';
import 'package:path_provider/path_provider.dart' as path_provider;
import 'package:sqlite3_async/sqlite3_async.dart';

void main() {
  runApp(const MyApp());
}

class MyApp extends StatelessWidget {
  const MyApp({super.key});

  [@override](/user/override)
  Widget build(BuildContext context) {
    return MaterialApp(
      title: 'Flutter Demo',
      theme: ThemeData(
        colorScheme: ColorScheme.fromSeed(seedColor: Colors.deepPurple),
        useMaterial3: true,
      ),
      home: const LoadingPage(),
    );
  }
}

class HomePage extends StatefulWidget {
  const HomePage({super.key});

  [@override](/user/override)
  State<HomePage> createState() => _HomePageState();
}

class _HomePageState extends State<HomePage> {
  final myController = TextEditingController();
  List<String> items = [];

  [@override](/user/override)
  void dispose() {
    myController.dispose();
    super.dispose();
  }

  [@override](/user/override)
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(title: const Text('Home Page')),
      body: Center(
        child: Column(
          mainAxisAlignment: MainAxisAlignment.start,
          children: [
            Padding(
              padding: const EdgeInsets.all(16.0),
              child: TextField(controller: myController, decoration: const InputDecoration(labelText: "Item")),
            ),
            ElevatedButton(onPressed: insertItem, child: const Text("Submit")),
            Text("Items: ${items.toString()}"),
          ],
        ),
      ),
    );
  }

  void insertItem() async {
    await StorageUtils.addItem(myController.text);
    var readItems = await StorageUtils.readItems();
    setState(() {
      items = readItems;
    });
  }
}

class LoadingPage extends StatelessWidget {
  const LoadingPage({super.key});

  [@override](/user/override)
  Widget build(BuildContext context) {
    return FutureBuilder<void>(
      future: StorageUtils.init(),
      builder: (context, snapshot) {
        if (snapshot.connectionState == ConnectionState.waiting) {
          return const Center(child: CircularProgressIndicator());
        } else {
          WidgetsBinding.instance.addPostFrameCallback((_) {
            Navigator.pushReplacement(context, MaterialPageRoute(builder: (_) => const HomePage()));
          });
          return Container();
        }
      },
    );
  }
}

class StorageUtils {
  static AsyncDatabase? _itemsDb;

  static Future<void> init() async {
    final databaseDir = await path_provider.getApplicationSupportDirectory();
    if (!await databaseDir.exists()) {
      await databaseDir.create(recursive: true);
    }
    final dbPath = '${databaseDir.path}/items.db';
    _itemsDb = await AsyncDatabase.open(dbPath);
    await _itemsDb!.execute("DROP TABLE IF EXISTS items");
    await _itemsDb!.execute("CREATE TABLE items(id INTEGER PRIMARY KEY AUTOINCREMENT, name TEXT NOT NULL)");
  }

  static Future<void> addItem(String name) => _itemsDb!.execute("INSERT INTO items(name) VALUES (?)", [name]);

  static Future<List<String>> readItems() async {
    return (await _itemsDb!.select("SELECT * FROM items")).map((e) => e["name"].toString()).toList();
  }
}