diff --git a/lib/database/database-factory.ts b/lib/database/database-factory.ts
new file mode 100644
index 0000000..abf4f47
--- /dev/null
+++ b/lib/database/database-factory.ts
@@ -0,0 +1,23 @@
+import { DatabaseInterface } from './types';
+import { SQLiteDatabase } from './sqlite-database';
+
+class DatabaseFactory {
+    private static instance: DatabaseInterface | null = null;
+
+    static getInstance(): DatabaseInterface {
+        if (!this.instance) {
+            // Metro 会根据平台自动选择正确的文件
+            // Web: sqlite-database.web.ts
+            // Native: sqlite-database.ts
+            this.instance = new SQLiteDatabase();
+        }
+        return this.instance!;
+    }
+
+    // 用于测试或重置实例
+    static resetInstance(): void {
+        this.instance = null;
+    }
+}
+
+export const database = DatabaseFactory.getInstance();
diff --git a/lib/database/database-test.ts b/lib/database/database-test.ts
new file mode 100644
index 0000000..fc1beb2
--- /dev/null
+++ b/lib/database/database-test.ts
@@ -0,0 +1,60 @@
+// 数据库架构测试文件
+import { database } from './database-factory';
+import { UploadTask } from './types';
+
+// 测试数据库基本功能
+export async function testDatabase() {
+    console.log('开始测试数据库功能...');
+    
+    try {
+        // 初始化数据库
+        await database.initUploadTable();
+        console.log('✓ 数据库初始化成功');
+        
+        // 测试插入任务
+        const testTask: Omit<UploadTask, 'created_at'> = {
+            uri: 'test://example.jpg',
+            filename: 'example.jpg',
+            status: 'pending',
+            progress: 0,
+            file_id: undefined
+        };
+        
+        await database.insertUploadTask(testTask);
+        console.log('✓ 任务插入成功');
+        
+        // 测试查询任务
+        const retrievedTask = await database.getUploadTaskStatus(testTask.uri);
+        if (retrievedTask) {
+            console.log('✓ 任务查询成功:', retrievedTask);
+        } else {
+            console.log('✗ 任务查询失败');
+        }
+        
+        // 测试更新任务状态
+        await database.updateUploadTaskStatus(testTask.uri, 'success', 'file123');
+        console.log('✓ 任务状态更新成功');
+        
+        // 测试获取所有任务
+        const allTasks = await database.getUploadTasks();
+        console.log('✓ 获取所有任务成功，数量:', allTasks.length);
+        
+        // 测试应用状态
+        await database.setAppState('test_key', 'test_value');
+        const stateValue = await database.getAppState('test_key');
+        console.log('✓ 应用状态测试成功:', stateValue);
+        
+        // 清理测试数据
+        await database.cleanUpUploadTasks();
+        console.log('✓ 数据清理成功');
+        
+        console.log('🎉 所有数据库测试通过！');
+        
+    } catch (error) {
+        console.error('❌ 数据库测试失败:', error);
+        throw error;
+    }
+}
+
+// 导出测试函数供调用
+export default testDatabase;
diff --git a/lib/database/empty-sqlite.js b/lib/database/empty-sqlite.js
new file mode 100644
index 0000000..aa6e3fc
--- /dev/null
+++ b/lib/database/empty-sqlite.js
@@ -0,0 +1,9 @@
+// 空的 SQLite 模块，用于 Web 环境
+console.warn('SQLite is not available in web environment');
+
+// 导出空的对象，避免导入错误
+module.exports = {
+    openDatabaseSync: () => {
+        throw new Error('SQLite is not available in web environment');
+    }
+};
diff --git a/lib/database/index.ts b/lib/database/index.ts
new file mode 100644
index 0000000..1c5595f
--- /dev/null
+++ b/lib/database/index.ts
@@ -0,0 +1,6 @@
+// 数据库模块统一导出
+export { DatabaseInterface, UploadTask } from './types';
+export { WebDatabase } from './web-database';
+export { SQLiteDatabase } from './sqlite-database';
+export { database } from './database-factory';
+export { testDatabase } from './database-test';
diff --git a/lib/database/sqlite-database.ts b/lib/database/sqlite-database.ts
new file mode 100644
index 0000000..9782d6c
--- /dev/null
+++ b/lib/database/sqlite-database.ts
@@ -0,0 +1,156 @@
+import { DatabaseInterface, UploadTask } from './types';
+
+export class SQLiteDatabase implements DatabaseInterface {
+    private db: any;
+
+    constructor() {
+        // 动态导入，避免在Web环境下加载
+        try {
+            const SQLite = require('expo-sqlite');
+            this.db = SQLite.openDatabaseSync('upload_status.db');
+            this.db.execSync('PRAGMA busy_timeout = 5000;');
+        } catch (error) {
+            console.error('Failed to initialize SQLite:', error);
+            throw new Error('SQLite is not available in this environment');
+        }
+    }
+
+    async initUploadTable(): Promise<void> {
+        console.log('Initializing upload tasks table...');
+        await this.db.execAsync(`
+            CREATE TABLE IF NOT EXISTS upload_tasks (
+                uri TEXT PRIMARY KEY NOT NULL,
+                filename TEXT NOT NULL,
+                status TEXT NOT NULL DEFAULT 'pending',
+                progress INTEGER NOT NULL DEFAULT 0,
+                file_id TEXT,
+                created_at INTEGER NOT NULL DEFAULT (strftime('%s', 'now'))
+            );
+        `);
+
+        // Add created_at column to existing table if it doesn't exist
+        const columns = await this.db.getAllAsync('PRAGMA table_info(upload_tasks);');
+        const columnExists = columns.some((column: any) => column.name === 'created_at');
+
+        if (!columnExists) {
+            console.log('Adding created_at column to upload_tasks table...');
+            await this.db.execAsync(`ALTER TABLE upload_tasks ADD COLUMN created_at INTEGER;`);
+            await this.db.execAsync(`UPDATE upload_tasks SET created_at = (strftime('%s', 'now')) WHERE created_at IS NULL;`);
+            console.log('created_at column added and populated.');
+        }
+        console.log('Upload tasks table initialized');
+
+        await this.db.execAsync(`
+            CREATE TABLE IF NOT EXISTS app_state (
+                key TEXT PRIMARY KEY NOT NULL,
+                value TEXT
+            );
+        `);
+        console.log('App state table initialized');
+    }
+
+    async insertUploadTask(task: Omit<UploadTask, 'created_at'>): Promise<void> {
+        console.log('Inserting upload task:', task.uri);
+        await this.db.runAsync(
+            'INSERT OR REPLACE INTO upload_tasks (uri, filename, status, progress, file_id, created_at) VALUES (?, ?, ?, ?, ?, ?)',
+            [task.uri, task.filename, task.status, task.progress, task.file_id ?? null, Math.floor(Date.now() / 1000)]
+        );
+    }
+
+    async getUploadTaskStatus(uri: string): Promise<UploadTask | null> {
+        console.log('Checking upload task status for:', uri);
+        const result = await this.db.getFirstAsync(
+            'SELECT uri, filename, status, progress, file_id, created_at FROM upload_tasks WHERE uri = ?;',
+            uri
+        );
+        return result || null;
+    }
+
+    async updateUploadTaskStatus(uri: string, status: UploadTask['status'], file_id?: string): Promise<void> {
+        if (file_id) {
+            await this.db.runAsync('UPDATE upload_tasks SET status = ?, file_id = ? WHERE uri = ?', [status, file_id, uri]);
+        } else {
+            await this.db.runAsync('UPDATE upload_tasks SET status = ? WHERE uri = ?', [status, uri]);
+        }
+    }
+
+    async updateUploadTaskProgress(uri: string, progress: number): Promise<void> {
+        await this.db.runAsync('UPDATE upload_tasks SET progress = ? WHERE uri = ?', [progress, uri]);
+    }
+
+    async getUploadTasks(): Promise<UploadTask[]> {
+        console.log('Fetching all upload tasks... time:', new Date().toLocaleString());
+        const results = await this.db.getAllAsync(
+            'SELECT uri, filename, status, progress, file_id, created_at FROM upload_tasks ORDER BY created_at DESC;'
+        );
+        return results;
+    }
+
+    async cleanUpUploadTasks(): Promise<void> {
+        console.log('Cleaning up completed/failed upload tasks...');
+        await this.db.runAsync(
+            "DELETE FROM upload_tasks WHERE status = 'success' OR status = 'failed' OR status = 'skipped';"
+        );
+    }
+
+    async getUploadTasksSince(timestamp: number): Promise<UploadTask[]> {
+        const rows = await this.db.getAllAsync(
+            'SELECT * FROM upload_tasks WHERE created_at >= ? ORDER BY created_at DESC',
+            [timestamp]
+        );
+        return rows;
+    }
+
+    async exist_pending_tasks(): Promise<boolean> {
+        const rows = await this.db.getAllAsync(
+            'SELECT * FROM upload_tasks WHERE status = "pending" OR status = "uploading"'
+        );
+        return rows.length > 0;
+    }
+
+    async filterExistingFiles(fileUris: string[]): Promise<string[]> {
+        if (fileUris.length === 0) {
+            return [];
+        }
+
+        const placeholders = fileUris.map(() => '?').join(',');
+        const query = `SELECT uri FROM upload_tasks WHERE uri IN (${placeholders}) AND status = 'success'`;
+
+        const existingFiles = await this.db.getAllAsync(query, fileUris);
+        const existingUris = new Set(existingFiles.map((f: { uri: string }) => f.uri));
+        const newFileUris = fileUris.filter(uri => !existingUris.has(uri));
+
+        console.log(`[DB] Total files: ${fileUris.length}, Existing successful files: ${existingUris.size}, New files to upload: ${newFileUris.length}`);
+
+        return newFileUris;
+    }
+
+    async setAppState(key: string, value: string | null): Promise<void> {
+        console.log(`Setting app state: ${key} = ${value}`);
+        await this.db.runAsync('INSERT OR REPLACE INTO app_state (key, value) VALUES (?, ?)', [key, value]);
+    }
+
+    async getAppState(key: string): Promise<string | null> {
+        const result = await this.db.getFirstAsync('SELECT value FROM app_state WHERE key = ?;', key);
+        return result?.value ?? null;
+    }
+
+    async executeSql(sql: string, params: any[] = []): Promise<any> {
+        try {
+            const isSelect = sql.trim().toLowerCase().startsWith('select');
+            if (isSelect) {
+                const results = this.db.getAllSync(sql, params);
+                return results;
+            } else {
+                const result = this.db.runSync(sql, params);
+                return {
+                    changes: result.changes,
+                    lastInsertRowId: result.lastInsertRowId,
+                };
+            }
+        } catch (error: any) {
+            console.error("Error executing SQL:", error);
+            return { error: error.message };
+        }
+    }
+}
diff --git a/lib/database/sqlite-database.web.ts b/lib/database/sqlite-database.web.ts
new file mode 100644
index 0000000..3b3ba1a
--- /dev/null
+++ b/lib/database/sqlite-database.web.ts
@@ -0,0 +1,140 @@
+import { DatabaseInterface, UploadTask } from './types';
+
+// Web 环境下的 SQLite 数据库实现（实际使用 localStorage）
+export class SQLiteDatabase implements DatabaseInterface {
+    private getStorageKey(table: string): string {
+        return `memowake_${table}`;
+    }
+
+    private getUploadTasksFromStorage(): UploadTask[] {
+        const data = localStorage.getItem(this.getStorageKey('upload_tasks'));
+        return data ? JSON.parse(data) : [];
+    }
+
+    private saveUploadTasks(tasks: UploadTask[]): void {
+        localStorage.setItem(this.getStorageKey('upload_tasks'), JSON.stringify(tasks));
+    }
+
+    private getAppStateData(): Record<string, string> {
+        const data = localStorage.getItem(this.getStorageKey('app_state'));
+        return data ? JSON.parse(data) : {};
+    }
+
+    private saveAppStateData(state: Record<string, string>): void {
+        localStorage.setItem(this.getStorageKey('app_state'), JSON.stringify(state));
+    }
+
+    async initUploadTable(): Promise<void> {
+        console.log('Initializing web storage tables (SQLite fallback)...');
+        // Web端不需要初始化表结构，localStorage会自动处理
+    }
+
+    async insertUploadTask(task: Omit<UploadTask, 'created_at'>): Promise<void> {
+        console.log('Inserting upload task:', task.uri);
+        const tasks = this.getUploadTasksFromStorage();
+        const existingIndex = tasks.findIndex(t => t.uri === task.uri);
+        const newTask: UploadTask = {
+            ...task,
+            created_at: Math.floor(Date.now() / 1000)
+        };
+
+        if (existingIndex >= 0) {
+            tasks[existingIndex] = newTask;
+        } else {
+            tasks.push(newTask);
+        }
+
+        this.saveUploadTasks(tasks);
+    }
+
+    async getUploadTaskStatus(uri: string): Promise<UploadTask | null> {
+        console.log('Checking upload task status for:', uri);
+        const tasks = this.getUploadTasksFromStorage();
+        return tasks.find(t => t.uri === uri) || null;
+    }
+
+    async updateUploadTaskStatus(uri: string, status: UploadTask['status'], file_id?: string): Promise<void> {
+        const tasks = this.getUploadTasksFromStorage();
+        const taskIndex = tasks.findIndex(t => t.uri === uri);
+        if (taskIndex >= 0) {
+            tasks[taskIndex].status = status;
+            if (file_id) {
+                tasks[taskIndex].file_id = file_id;
+            }
+            this.saveUploadTasks(tasks);
+        }
+    }
+
+    async updateUploadTaskProgress(uri: string, progress: number): Promise<void> {
+        const tasks = this.getUploadTasksFromStorage();
+        const taskIndex = tasks.findIndex(t => t.uri === uri);
+        if (taskIndex >= 0) {
+            tasks[taskIndex].progress = progress;
+            this.saveUploadTasks(tasks);
+        }
+    }
+
+    async getUploadTasks(): Promise<UploadTask[]> {
+        console.log('Fetching all upload tasks... time:', new Date().toLocaleString());
+        const tasks = this.getUploadTasksFromStorage();
+        return tasks.sort((a, b) => b.created_at - a.created_at);
+    }
+
+    async cleanUpUploadTasks(): Promise<void> {
+        console.log('Cleaning up completed/failed upload tasks...');
+        const tasks = this.getUploadTasksFromStorage();
+        const filteredTasks = tasks.filter(t =>
+            t.status !== 'success' && t.status !== 'failed' && t.status !== 'skipped'
+        );
+        this.saveUploadTasks(filteredTasks);
+    }
+
+    async getUploadTasksSince(timestamp: number): Promise<UploadTask[]> {
+        const tasks = this.getUploadTasksFromStorage();
+        const filteredTasks = tasks.filter(t => t.created_at >= timestamp);
+        return filteredTasks.sort((a, b) => b.created_at - a.created_at);
+    }
+
+    async exist_pending_tasks(): Promise<boolean> {
+        const tasks = this.getUploadTasksFromStorage();
+        return tasks.some(t => t.status === 'pending' || t.status === 'uploading');
+    }
+
+    async filterExistingFiles(fileUris: string[]): Promise<string[]> {
+        if (fileUris.length === 0) {
+            return [];
+        }
+
+        const tasks = this.getUploadTasksFromStorage();
+        const successfulUris = new Set(
+            tasks.filter(t => t.status === 'success').map(t => t.uri)
+        );
+
+        const newFileUris = fileUris.filter(uri => !successfulUris.has(uri));
+
+        console.log(`[WebDB] Total files: ${fileUris.length}, Existing successful files: ${successfulUris.size}, New files to upload: ${newFileUris.length}`);
+
+        return newFileUris;
+    }
+
+    async setAppState(key: string, value: string | null): Promise<void> {
+        console.log(`Setting app state: ${key} = ${value}`);
+        const state = this.getAppStateData();
+        if (value === null) {
+            delete state[key];
+        } else {
+            state[key] = value;
+        }
+        this.saveAppStateData(state);
+    }
+
+    async getAppState(key: string): Promise<string | null> {
+        const state = this.getAppStateData();
+        return state[key] || null;
+    }
+
+    async executeSql(sql: string, params: any[] = []): Promise<any> {
+        console.warn('SQL execution not supported in web environment:', sql);
+        return { error: 'SQL execution not supported in web environment' };
+    }
+}
diff --git a/lib/database/types.ts b/lib/database/types.ts
new file mode 100644
index 0000000..848aee6
--- /dev/null
+++ b/lib/database/types.ts
@@ -0,0 +1,24 @@
+export type UploadTask = {
+    uri: string;
+    filename: string;
+    status: 'pending' | 'uploading' | 'success' | 'failed' | 'skipped';
+    progress: number; // 0-100
+    file_id?: string; // 后端返回的文件ID
+    created_at: number; // unix timestamp
+};
+
+export interface DatabaseInterface {
+    initUploadTable(): Promise<void>;
+    insertUploadTask(task: Omit<UploadTask, 'created_at'>): Promise<void>;
+    getUploadTaskStatus(uri: string): Promise<UploadTask | null>;
+    updateUploadTaskStatus(uri: string, status: UploadTask['status'], file_id?: string): Promise<void>;
+    updateUploadTaskProgress(uri: string, progress: number): Promise<void>;
+    getUploadTasks(): Promise<UploadTask[]>;
+    cleanUpUploadTasks(): Promise<void>;
+    getUploadTasksSince(timestamp: number): Promise<UploadTask[]>;
+    exist_pending_tasks(): Promise<boolean>;
+    filterExistingFiles(fileUris: string[]): Promise<string[]>;
+    setAppState(key: string, value: string | null): Promise<void>;
+    getAppState(key: string): Promise<string | null>;
+    executeSql(sql: string, params?: any[]): Promise<any>;
+}
diff --git a/lib/database/web-database.ts b/lib/database/web-database.ts
new file mode 100644
index 0000000..38d7201
--- /dev/null
+++ b/lib/database/web-database.ts
@@ -0,0 +1,139 @@
+import { DatabaseInterface, UploadTask } from './types';
+
+export class WebDatabase implements DatabaseInterface {
+    private getStorageKey(table: string): string {
+        return `memowake_${table}`;
+    }
+
+    private getUploadTasksFromStorage(): UploadTask[] {
+        const data = localStorage.getItem(this.getStorageKey('upload_tasks'));
+        return data ? JSON.parse(data) : [];
+    }
+
+    private saveUploadTasks(tasks: UploadTask[]): void {
+        localStorage.setItem(this.getStorageKey('upload_tasks'), JSON.stringify(tasks));
+    }
+
+    private getAppStateData(): Record<string, string> {
+        const data = localStorage.getItem(this.getStorageKey('app_state'));
+        return data ? JSON.parse(data) : {};
+    }
+
+    private saveAppStateData(state: Record<string, string>): void {
+        localStorage.setItem(this.getStorageKey('app_state'), JSON.stringify(state));
+    }
+
+    async initUploadTable(): Promise<void> {
+        console.log('Initializing web storage tables...');
+        // Web端不需要初始化表结构，localStorage会自动处理
+    }
+
+    async insertUploadTask(task: Omit<UploadTask, 'created_at'>): Promise<void> {
+        console.log('Inserting upload task:', task.uri);
+        const tasks = this.getUploadTasksFromStorage();
+        const existingIndex = tasks.findIndex(t => t.uri === task.uri);
+        const newTask: UploadTask = {
+            ...task,
+            created_at: Math.floor(Date.now() / 1000)
+        };
+
+        if (existingIndex >= 0) {
+            tasks[existingIndex] = newTask;
+        } else {
+            tasks.push(newTask);
+        }
+
+        this.saveUploadTasks(tasks);
+    }
+
+    async getUploadTaskStatus(uri: string): Promise<UploadTask | null> {
+        console.log('Checking upload task status for:', uri);
+        const tasks = this.getUploadTasksFromStorage();
+        return tasks.find(t => t.uri === uri) || null;
+    }
+
+    async updateUploadTaskStatus(uri: string, status: UploadTask['status'], file_id?: string): Promise<void> {
+        const tasks = this.getUploadTasksFromStorage();
+        const taskIndex = tasks.findIndex(t => t.uri === uri);
+        if (taskIndex >= 0) {
+            tasks[taskIndex].status = status;
+            if (file_id) {
+                tasks[taskIndex].file_id = file_id;
+            }
+            this.saveUploadTasks(tasks);
+        }
+    }
+
+    async updateUploadTaskProgress(uri: string, progress: number): Promise<void> {
+        const tasks = this.getUploadTasksFromStorage();
+        const taskIndex = tasks.findIndex(t => t.uri === uri);
+        if (taskIndex >= 0) {
+            tasks[taskIndex].progress = progress;
+            this.saveUploadTasks(tasks);
+        }
+    }
+
+    async getUploadTasks(): Promise<UploadTask[]> {
+        console.log('Fetching all upload tasks... time:', new Date().toLocaleString());
+        const tasks = this.getUploadTasksFromStorage();
+        return tasks.sort((a, b) => b.created_at - a.created_at);
+    }
+
+    async cleanUpUploadTasks(): Promise<void> {
+        console.log('Cleaning up completed/failed upload tasks...');
+        const tasks = this.getUploadTasksFromStorage();
+        const filteredTasks = tasks.filter(t =>
+            t.status !== 'success' && t.status !== 'failed' && t.status !== 'skipped'
+        );
+        this.saveUploadTasks(filteredTasks);
+    }
+
+    async getUploadTasksSince(timestamp: number): Promise<UploadTask[]> {
+        const tasks = this.getUploadTasksFromStorage();
+        const filteredTasks = tasks.filter(t => t.created_at >= timestamp);
+        return filteredTasks.sort((a, b) => b.created_at - a.created_at);
+    }
+
+    async exist_pending_tasks(): Promise<boolean> {
+        const tasks = this.getUploadTasksFromStorage();
+        return tasks.some(t => t.status === 'pending' || t.status === 'uploading');
+    }
+
+    async filterExistingFiles(fileUris: string[]): Promise<string[]> {
+        if (fileUris.length === 0) {
+            return [];
+        }
+
+        const tasks = this.getUploadTasksFromStorage();
+        const successfulUris = new Set(
+            tasks.filter(t => t.status === 'success').map(t => t.uri)
+        );
+
+        const newFileUris = fileUris.filter(uri => !successfulUris.has(uri));
+
+        console.log(`[WebDB] Total files: ${fileUris.length}, Existing successful files: ${successfulUris.size}, New files to upload: ${newFileUris.length}`);
+
+        return newFileUris;
+    }
+
+    async setAppState(key: string, value: string | null): Promise<void> {
+        console.log(`Setting app state: ${key} = ${value}`);
+        const state = this.getAppStateData();
+        if (value === null) {
+            delete state[key];
+        } else {
+            state[key] = value;
+        }
+        this.saveAppStateData(state);
+    }
+
+    async getAppState(key: string): Promise<string | null> {
+        const state = this.getAppStateData();
+        return state[key] || null;
+    }
+
+    async executeSql(sql: string, params: any[] = []): Promise<any> {
+        console.warn('SQL execution not supported in web environment:', sql);
+        return { error: 'SQL execution not supported in web environment' };
+    }
+}
diff --git a/lib/db.ts b/lib/db.ts
index 5aadded..217cb12 100644
--- a/lib/db.ts
+++ b/lib/db.ts
@@ -1,176 +1,23 @@
-import * as SQLite from 'expo-sqlite';
+// 使用数据库接口架构，支持 Web 和移动端
+import { database } from './database/database-factory';
+import { UploadTask } from './database/types';
 
-const db = SQLite.openDatabaseSync('upload_status.db');
-
-// Set a busy timeout to handle concurrent writes and avoid "database is locked" errors.
-// This will make SQLite wait for 5 seconds if the database is locked by another process.
-db.execSync('PRAGMA busy_timeout = 5000;');
-
-export type UploadTask = {
-    uri: string;
-    filename: string;
-    status: 'pending' | 'uploading' | 'success' | 'failed' | 'skipped';
-    progress: number; // 0-100
-    file_id?: string; // 后端返回的文件ID
-    created_at: number; // unix timestamp
-};
-
-// 初始化表
-export async function initUploadTable() {
-    console.log('Initializing upload tasks table...');
-    await db.execAsync(`
-        CREATE TABLE IF NOT EXISTS upload_tasks (
-            uri TEXT PRIMARY KEY NOT NULL,
-            filename TEXT NOT NULL,
-            status TEXT NOT NULL DEFAULT 'pending',
-            progress INTEGER NOT NULL DEFAULT 0,
-            file_id TEXT,
-            created_at INTEGER NOT NULL DEFAULT (strftime('%s', 'now'))
-        );
-    `);
-
-    // Add created_at column to existing table if it doesn't exist
-    const columns = await db.getAllAsync('PRAGMA table_info(upload_tasks);');
-    const columnExists = columns.some((column: any) => column.name === 'created_at');
-
-    if (!columnExists) {
-        console.log('Adding created_at column to upload_tasks table...');
-        // SQLite doesn't support non-constant DEFAULT values on ALTER TABLE.
-        // So we add the column, then update existing rows.
-        await db.execAsync(`ALTER TABLE upload_tasks ADD COLUMN created_at INTEGER;`);
-        await db.execAsync(`UPDATE upload_tasks SET created_at = (strftime('%s', 'now')) WHERE created_at IS NULL;`);
-        console.log('created_at column added and populated.');
-    }
-    console.log('Upload tasks table initialized');
-
-    await db.execAsync(`
-        CREATE TABLE IF NOT EXISTS app_state (
-            key TEXT PRIMARY KEY NOT NULL,
-            value TEXT
-        );
-    `);
-    console.log('App state table initialized');
-}
-
-// 插入新的上传任务
-export async function insertUploadTask(task: Omit<UploadTask, 'created_at'>) {
-    console.log('Inserting upload task:', task.uri);
-    await db.runAsync(
-        'INSERT OR REPLACE INTO upload_tasks (uri, filename, status, progress, file_id, created_at) VALUES (?, ?, ?, ?, ?, ?)',
-        [task.uri, task.filename, task.status, task.progress, task.file_id ?? null, Math.floor(Date.now() / 1000)]
-    );
-}
-
-// 检查文件是否已上传或正在上传
-export async function getUploadTaskStatus(uri: string): Promise<UploadTask | null> {
-    console.log('Checking upload task status for:', uri);
-    const result = await db.getFirstAsync<UploadTask>(
-        'SELECT uri, filename, status, progress, file_id, created_at FROM upload_tasks WHERE uri = ?;',
-        uri
-    );
-    return result || null;
-}
-
-// 更新上传任务的状态
-export async function updateUploadTaskStatus(uri: string, status: UploadTask['status'], file_id?: string) {
-    if (file_id) {
-        await db.runAsync('UPDATE upload_tasks SET status = ?, file_id = ? WHERE uri = ?', [status, file_id, uri]);
-    } else {
-        await db.runAsync('UPDATE upload_tasks SET status = ? WHERE uri = ?', [status, uri]);
-    }
-}
-
-// 更新上传任务的进度
-export async function updateUploadTaskProgress(uri: string, progress: number) {
-    await db.runAsync('UPDATE upload_tasks SET progress = ? WHERE uri = ?', [progress, uri]);
-}
-
-// 获取所有上传任务
-export async function getUploadTasks(): Promise<UploadTask[]> {
-    console.log('Fetching all upload tasks... time:', new Date().toLocaleString());
-    const results = await db.getAllAsync<UploadTask>(
-        'SELECT uri, filename, status, progress, file_id, created_at FROM upload_tasks ORDER BY created_at DESC;'
-    );
-    return results;
-}
-
-// 清理已完成或失败的任务 (可选，根据需求添加)
-export async function cleanUpUploadTasks(): Promise<void> {
-    console.log('Cleaning up completed/failed upload tasks...');
-    await db.runAsync(
-        "DELETE FROM upload_tasks WHERE status = 'success' OR status = 'failed' OR status = 'skipped';"
-    );
-}
-
-// 获取某个时间点之后的所有上传任务
-export async function getUploadTasksSince(timestamp: number): Promise<UploadTask[]> {
-    const rows = await db.getAllAsync<UploadTask>(
-        'SELECT * FROM upload_tasks WHERE created_at >= ? ORDER BY created_at DESC',
-        [timestamp]
-    );
-    return rows;
-}
-
-export async function exist_pending_tasks(): Promise<boolean> {
-    const rows = await db.getAllAsync<UploadTask>(
-        'SELECT * FROM upload_tasks WHERE status = "pending" OR status = "uploading"'
-    );
-    return rows.length > 0;
-}
-
-// 检查一组文件URI，返回那些在数据库中不存在或是未成功上传的文件的URI
-export async function filterExistingFiles(fileUris: string[]): Promise<string[]> {
-    if (fileUris.length === 0) {
-        return [];
-    }
-
-    // 创建占位符字符串 '?,?,?'
-    const placeholders = fileUris.map(() => '?').join(',');
-
-    // 查询已经存在且状态为 'success' 的任务
-    const query = `SELECT uri FROM upload_tasks WHERE uri IN (${placeholders}) AND status = 'success'`;
-
-    const existingFiles = await db.getAllAsync<{ uri: string }>(query, fileUris);
-    const existingUris = new Set(existingFiles.map(f => f.uri));
-
-    // 过滤出新文件
-    const newFileUris = fileUris.filter(uri => !existingUris.has(uri));
-
-    console.log(`[DB] Total files: ${fileUris.length}, Existing successful files: ${existingUris.size}, New files to upload: ${newFileUris.length}`);
-
-    return newFileUris;
-}
-
-// 设置全局状态值
-export async function setAppState(key: string, value: string | null): Promise<void> {
-    console.log(`Setting app state: ${key} = ${value}`);
-    await db.runAsync('INSERT OR REPLACE INTO app_state (key, value) VALUES (?, ?)', [key, value]);
-}
-
-// 获取全局状态值
-export async function getAppState(key: string): Promise<string | null> {
-    const result = await db.getFirstAsync<{ value: string }>('SELECT value FROM app_state WHERE key = ?;', key);
-    return result?.value ?? null;
-}
-
-// for debug page
-export async function executeSql(sql: string, params: any[] = []): Promise<any> {
-    try {
-        // Trim and check if it's a SELECT query
-        const isSelect = sql.trim().toLowerCase().startsWith('select');
-        if (isSelect) {
-            const results = db.getAllSync(sql, params);
-            return results;
-        } else {
-            const result = db.runSync(sql, params);
-            return {
-                changes: result.changes,
-                lastInsertRowId: result.lastInsertRowId,
-            };
-        }
-    } catch (error: any) {
-        console.error("Error executing SQL:", error);
-        return { error: error.message };
-    }
-}
+// 重新导出类型
+export type { UploadTask };
 
+// 重新导出所有数据库函数，使用统一接口
+export const initUploadTable = () => database.initUploadTable();
+export const insertUploadTask = (task: Omit<UploadTask, 'created_at'>) => database.insertUploadTask(task);
+export const getUploadTaskStatus = (uri: string) => database.getUploadTaskStatus(uri);
+export const updateUploadTaskStatus = (uri: string, status: UploadTask['status'], file_id?: string) =>
+    database.updateUploadTaskStatus(uri, status, file_id);
+export const updateUploadTaskProgress = (uri: string, progress: number) =>
+    database.updateUploadTaskProgress(uri, progress);
+export const getUploadTasks = () => database.getUploadTasks();
+export const cleanUpUploadTasks = () => database.cleanUpUploadTasks();
+export const getUploadTasksSince = (timestamp: number) => database.getUploadTasksSince(timestamp);
+export const exist_pending_tasks = () => database.exist_pending_tasks();
+export const filterExistingFiles = (fileUris: string[]) => database.filterExistingFiles(fileUris);
+export const setAppState = (key: string, value: string | null) => database.setAppState(key, value);
+export const getAppState = (key: string) => database.getAppState(key);
+export const executeSql = (sql: string, params: any[] = []) => database.executeSql(sql, params);
diff --git a/metro.config.js b/metro.config.js
index 7ba56c4..a20435c 100644
--- a/metro.config.js
+++ b/metro.config.js
@@ -19,6 +19,15 @@ config.resolver = {
     ...config.resolver?.alias,
     '@/': path.resolve(__dirname, './'),
   },
+  platforms: ['ios', 'android', 'native', 'web'],
 };
 
+// Web 环境下的模块别名
+if (process.env.EXPO_PLATFORM === 'web') {
+  config.resolver.alias = {
+    ...config.resolver.alias,
+    'expo-sqlite': path.resolve(__dirname, './lib/database/empty-sqlite.js'),
+  };
+}
+
 module.exports = withNativeWind(config, { input: './global.css' });
\ No newline at end of file