release: v0.5.0 — 升级 MetonaEditor 0.4.0 / MetonaToast 0.5.0，数据库迁移 MetonaSqlark 0.4.1

- 编辑器升级 0.4.0：TypeScript 全模块重构、启用浮动格式工具栏 - 通知升级 0.5.0：钩子系统、新增动画 - 移除 Dexie.js，迁移至 MetonaSqlark 0.4.1（AriaEngine：LSM-Tree + WAL + MVCC） - 数据库更换为 MarkLiteV2，旧 Dexie 数据放弃 - 修复 Editor 组件无条件重渲染（getActiveTab 返回新引用） - 更新关于弹框、README、DESIGN 文档
2026-08-09 15:45:36 +08:00
parent d6ae9e3c8e
commit 20eb39efc5
47 changed files with 4981 additions and 3050 deletions
@@ -0,0 +1,763 @@
+<!DOCTYPE html>
+<html lang="zh-CN">
+<head>
+<meta charset="UTF-8">
+<meta name="viewport" content="width=device-width, initial-scale=1.0">
+<title>🧪 在线演示 — MetonaSqlark v0.4.1</title>
+<link rel="icon" href="data:image/svg+xml,<svg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 32 32'><rect width='32' height='32' rx='8' fill='%236366f1'/><text x='16' y='22' text-anchor='middle' font-size='20' fill='white'>◈</text></svg>">
+<style>
+  :root {
+    --bg:#0a0a0f; --surface:#0d1117; --surface2:#161b22; --border:#30363d;
+    --primary:#6366f1; --accent:#06b6d4; --accent2:#ec4899; --green:#22c55e;
+    --text:#e2e8f0; --text2:#8b949e; --radius:12px;
+    --gradient:linear-gradient(135deg,#6366f1,#06b6d4,#ec4899);
+  }
+  * { margin:0; padding:0; box-sizing:border-box; }
+  body { font-family:'Inter',-apple-system,system-ui,sans-serif; background:var(--bg); color:var(--text); height:100vh; overflow:hidden; }
+  header {
+    height:56px; display:flex; align-items:center; justify-content:space-between; padding:0 24px;
+    background:var(--surface); border-bottom:1px solid var(--border); z-index:10; position:relative;
+  }
+  .logo { font-weight:800; font-size:1.1rem; display:flex; align-items:center; gap:10px; }
+  .logo .icon { width:28px; height:28px; border-radius:7px; background:var(--gradient); display:flex; align-items:center; justify-content:center; font-size:0.85rem; font-weight:900; color:#fff; }
+  .logo span { background:var(--gradient); -webkit-background-clip:text; -webkit-text-fill-color:transparent; }
+  nav { display:flex; gap:20px; }
+  nav a { color:var(--text2); text-decoration:none; font-size:0.88rem; transition:.2s; }
+  nav a:hover,.nav-active { color:var(--text); }
+  .status { display:flex; align-items:center; gap:8px; font-size:0.82rem; color:var(--text2); }
+  .status .dot { width:7px; height:7px; border-radius:50%; background:var(--green); animation:pulse 2s infinite; }
+  @keyframes pulse { 0%,100%{opacity:1} 50%{opacity:.3} }
+  .main { display:flex; height:calc(100vh - 56px); }
+  .editor-panel { flex:1; display:flex; flex-direction:column; border-right:1px solid var(--border); min-width:400px; }
+  .result-panel { flex:1; display:flex; flex-direction:column; min-width:400px; }
+  .panel-header {
+    padding:12px 20px; font-size:0.78rem; font-weight:600; text-transform:uppercase;
+    letter-spacing:1px; color:var(--text2); border-bottom:1px solid var(--border);
+    display:flex; align-items:center; justify-content:space-between;
+  }
+  .panel-header .badge {
+    font-size:0.7rem; padding:3px 10px; border-radius:999px; background:var(--surface2);
+    border:1px solid var(--border); text-transform:none; letter-spacing:0;
+  }
+  .editor-area { flex:1; display:flex; flex-direction:column; }
+  #sql-input {
+    flex:1; background:var(--surface); color:var(--text); border:none; padding:20px;
+    font-family:'JetBrains Mono','Fira Code',monospace; font-size:0.9rem; line-height:1.8;
+    resize:none; outline:none; caret-color:var(--primary);
+  }
+  #sql-input::placeholder { color:var(--text2); opacity:0.5; }
+  .toolbar { display:flex; gap:8px; padding:12px 20px; border-top:1px solid var(--border); background:var(--surface2); flex-wrap:wrap; }
+  .btn {
+    display:inline-flex; align-items:center; gap:6px; padding:10px 20px; border-radius:8px;
+    font-weight:600; font-size:0.85rem; cursor:pointer; border:none; transition:.25s; font-family:inherit;
+  }
+  .btn-run { background:var(--gradient); color:#fff; box-shadow:0 4px 15px rgba(99,102,241,0.35); }
+  .btn-run:hover { transform:translateY(-1px); box-shadow:0 6px 25px rgba(99,102,241,0.5); }
+  .btn-run:active { transform:scale(0.97); }
+  .btn-clear { background:var(--surface2); color:var(--text2); border:1px solid var(--border); }
+  .btn-clear:hover { color:var(--text); border-color:var(--text2); }
+  .btn-preset { background:transparent; color:var(--accent); border:1px solid var(--accent); font-size:0.78rem; padding:6px 14px; }
+  .btn-preset:hover { background:rgba(6,182,212,0.12); }
+  .result-content { flex:1; overflow-y:auto; padding:20px; }
+  .result-table { width:100%; border-collapse:collapse; font-size:0.85rem; }
+  .result-table th { text-align:left; padding:10px 14px; background:var(--surface2); color:var(--accent); font-weight:600; border-bottom:2px solid var(--border); position:sticky; top:0; z-index:1; }
+  .result-table td { padding:8px 14px; border-bottom:1px solid var(--border); color:var(--text2); max-width:250px; overflow:hidden; text-overflow:ellipsis; white-space:nowrap; }
+  .result-table tr:hover td { background:rgba(99,102,241,0.04); }
+  .empty-state { display:flex; flex-direction:column; align-items:center; justify-content:center; height:100%; color:var(--text2); gap:12px; }
+  .empty-state .icon { font-size:3rem; opacity:0.3; }
+  .error-box { background:rgba(239,68,68,0.1); border:1px solid rgba(239,68,68,0.3); border-radius:10px; padding:16px; color:#f87171; font-family:'JetBrains Mono',monospace; font-size:0.82rem; margin-bottom:16px; }
+  .success-box { background:rgba(34,197,94,0.1); border:1px solid rgba(34,197,94,0.3); border-radius:10px; padding:12px 16px; color:#4ade80; font-size:0.85rem; margin-bottom:16px; }
+  .sql-tag { display:inline-block; background:var(--surface2); border:1px solid var(--border); border-radius:6px; padding:4px 12px; font-family:'JetBrains Mono',monospace; font-size:0.75rem; color:var(--accent); margin-bottom:8px; }
+  ::-webkit-scrollbar { width:6px; height:6px; }
+  ::-webkit-scrollbar-track { background:transparent; }
+  ::-webkit-scrollbar-thumb { background:var(--border); border-radius:3px; }
+  @media(max-width:900px){ .main { flex-direction:column; } .editor-panel,.result-panel { min-width:auto; } .editor-panel { height:50%; } }
+</style>
+</head>
+<body>
+
+<header>
+  <div class="logo"><div class="icon">◈</div><span>MetonaSqlark</span></div>
+  <nav>
+    <a href="index.html">首页</a>
+    <a href="docs.html">文档</a>
+    <a href="demo.html" class="nav-active">演示</a>
+    <a href="benchmark.html">基准</a>
+  </nav>
+  <div class="status"><span class="dot" id="engine-dot"></span> <span id="engine-status">Memory</span> 模式 — v0.4.1</div>
+  <button class="btn btn-preset" onclick="switchEngine('memory')" id="btn-memory" style="margin:6px 4px 6px 0;padding:6px 12px;">⚡ Memory</button>
+  <button class="btn btn-preset" onclick="switchEngine('aria')" id="btn-aria" style="margin:6px 0;padding:6px 12px;color:#ec4899;border-color:#ec4899;">🌲 Aria</button>
+</header>
+
+<div class="main">
+  <div class="editor-panel">
+    <div class="editor-area">
+<textarea id="sql-input" placeholder="输入 SQL 语句...&#10;&#10;SELECT * FROM users;&#10;INSERT INTO users VALUES ('4', 'Diana', 'diana@test.com', 28);&#10;SELECT u.name, o.amount FROM users u INNER JOIN orders o ON u.id = o.user_id;">-- 🚀 MetonaSqlark v0.4.1 在线演示
+	-- 已预置 users / orders / products 表数据
+	-- 新特性: ALTER TABLE · TRUNCATE TABLE · WAL同步 · MVCC · SQL注入防护
+	
+	-- 查看所有数据
+	SELECT * FROM users;
+	
+	-- 条件查询 + 排序
+	SELECT name, age FROM users WHERE age > 25 ORDER BY age DESC;
+	
+	-- JOIN 多表关联
+	SELECT u.name, o.product, o.amount
+	FROM users u INNER JOIN orders o ON u.id = o.user_id;
+	
+	-- 聚合统计
+	SELECT COUNT(*) as total_users, AVG(age) as avg_age FROM users;</textarea>
+      <div class="toolbar">
+        <button class="btn btn-run" onclick="runQuery()">▶ 执行 (Ctrl+Enter)</button>
+        <button class="btn btn-clear" onclick="clearResults()">🗑 清空</button>
+        <span style="flex:1"></span>
+        <button class="btn btn-preset" onclick="loadPreset('all')">📋 全数据</button>
+        <button class="btn btn-preset" onclick="loadPreset('join')">🔗 JOIN</button>
+        <button class="btn btn-preset" onclick="loadPreset('agg')">📊 聚合</button>
+        <button class="btn btn-preset" onclick="loadPreset('ddl')">🏗 DDL</button>
+        <button class="btn btn-preset" onclick="loadPreset('crud')">✏️ CRUD</button>
+        <button class="btn btn-preset" onclick="loadPreset('subquery')">🔍 子查询</button>
+        <button class="btn btn-preset" onclick="loadPreset('tx')">🔒 事务</button>
+        <button class="btn btn-preset" onclick="loadPreset('scalar')">🎯 标量子查询</button>
+<button class="btn btn-preset" onclick="loadPreset('cascade')">🔗 级联</button>
+	        <button class="btn btn-preset" onclick="loadPreset('adv')">🧪 高级</button>
+        <button class="btn btn-preset" onclick="loadPreset('alter')">🏗 ALTER</button>
+        <button class="btn btn-preset" onclick="loadPreset('truncate')">🗑 TRUNCATE</button>
+        <button class="btn btn-preset" onclick="loadPreset('casewhen')">🎯 CASE WHEN</button>
+        <button class="btn btn-preset" onclick="loadPreset('union')">🔀 UNION</button>
+        <button class="btn btn-preset" onclick="loadPreset('insertselect')">📥 INSERT SELECT</button>
+        <button class="btn btn-preset" onclick="loadPreset('exists')">🔍 EXISTS</button>
+        <button class="btn btn-preset" onclick="loadPreset('index')">🗂 索引</button>
+        <button class="btn btn-preset" onclick="loadPreset('multistmt')">📜 多语句/事务</button>
+        <button class="btn btn-preset" onclick="loadPreset('v040')" style="color:#22c55e;border-color:#22c55e;">🚰 v0.4.0 新特性</button>
+        <button class="btn btn-preset" onclick="loadPreset('aria')" style="color:#ec4899;border-color:#ec4899;">🌲 Aria</button>
+      </div>
+    </div>
+  </div>
+
+  <div class="result-panel">
+    <div class="panel-header">
+      <span>📊 查询结果</span>
+      <span class="badge" id="row-count">0 行</span>
+    </div>
+    <div class="result-content" id="result-area">
+      <div class="empty-state">
+        <div class="icon">⚡</div>
+        <div>执行 SQL 查询以查看结果</div>
+        <div style="font-size:0.8rem;opacity:0.6">Ctrl + Enter 快捷执行 · 支持多语句</div>
+      </div>
+    </div>
+  </div>
+</div>
+
+<script src="../dist/metona-sqlark.js"></script>
+<script>
+// Resolve global: try both MetonaSqlark and MeSqlark
+const globalNs = window.MetonaSqlark || window.MeSqlark || {};
+const { MetonaSqlark, MeSqlark, create } = globalNs;
+const DBClass = MetonaSqlark || MeSqlark;
+
+let db = null;
+const resultArea = document.getElementById('result-area');
+const rowCount = document.getElementById('row-count');
+const sqlInput = document.getElementById('sql-input');
+
+// Init database
+let currentEngine = 'memory';
+
+async function initDB() {
+  try {
+    const engine = currentEngine;
+    // 关闭旧实例（预设重置/引擎切换时数据回到初始状态）
+    if (db) { try { await db.close(); } catch { /* ignore */ } }
+    db = new DBClass({ name: 'demo', mode: engine });
+    await db.init();
+
+    // v0.4.1: Aria 引擎持久化 — 每次加载清空上次演示数据，保证演示确定性
+    if (engine === 'aria' && typeof db.getEngine().clearAll === 'function') {
+      await db.getEngine().clearAll();
+    }
+
+    await seedDemoData(db);
+    renderInfo(`✅ ${engine === 'aria' ? '🌲 AriaEngine（LSM-Tree + WAL + MVCC）' : '⚡ Memory'} 引擎已就绪`);
+  } catch (e) {
+    renderError('数据库初始化失败: ' + e.message);
+  }
+}
+
+// 建表 + 种子数据（每次预设重置/引擎切换后重建，保证演示可预期）
+async function seedDemoData(db) {
+  await db.defineTable('users', {
+    id: { type: 'string', primaryKey: true },
+    name: { type: 'string', required: true },
+    email: { type: 'string' },
+    age: { type: 'number', default: 0 },
+  });
+  await db.defineTable('orders', {
+    id: { type: 'string', primaryKey: true },
+    user_id: { type: 'string' },
+    product: { type: 'string' },
+    amount: { type: 'number' },
+    quantity: { type: 'number', default: 1 },
+  });
+  await db.defineTable('products', {
+    id: { type: 'string', primaryKey: true },
+    name: { type: 'string', required: true },
+    price: { type: 'number', default: 0 },
+    category: { type: 'string' },
+  });
+
+  // Seed data
+  await db.table('users').insertMany([
+    { id: '1', name: 'Alice', email: 'alice@demo.com', age: 30 },
+    { id: '2', name: 'Bob', email: 'bob@demo.com', age: 25 },
+    { id: '3', name: 'Charlie', email: 'charlie@demo.com', age: 35 },
+    { id: '4', name: 'Diana', email: 'diana@demo.com', age: 28 },
+    { id: '5', name: 'Eve', email: 'eve@demo.com', age: 22 },
+  ]);
+  await db.table('orders').insertMany([
+    { id: 'o1', user_id: '1', product: 'Laptop', amount: 1200, quantity: 1 },
+    { id: 'o2', user_id: '1', product: 'Mouse', amount: 50, quantity: 2 },
+    { id: 'o3', user_id: '2', product: 'Keyboard', amount: 150, quantity: 1 },
+    { id: 'o4', user_id: '3', product: 'Monitor', amount: 400, quantity: 1 },
+    { id: 'o5', user_id: '3', product: 'Cable', amount: 20, quantity: 3 },
+  ]);
+  await db.table('products').insertMany([
+    { id: 'p1', name: 'Laptop', price: 1200, category: 'Electronics' },
+    { id: 'p2', name: 'Mouse', price: 50, category: 'Accessories' },
+    { id: 'p3', name: 'Keyboard', price: 150, category: 'Accessories' },
+  ]);
+}
+
+// v0.4.1: 切换存储引擎（重建数据库实例）
+async function switchEngine(engine) {
+  if (engine === currentEngine) return;
+  currentEngine = engine;
+  document.getElementById('btn-memory').style.opacity = engine === 'memory' ? '1' : '0.6';
+  document.getElementById('btn-aria').style.opacity = engine === 'aria' ? '1' : '0.6';
+  document.getElementById('engine-status').textContent = engine === 'aria' ? '🌲 Aria' : '⚡ Memory';
+  document.getElementById('engine-dot').style.background = engine === 'aria' ? '#ec4899' : '';
+  renderInfo(`⏳ 正在初始化 ${engine === 'aria' ? 'Aria' : 'Memory'} 引擎…`);
+  await initDB();
+}
+
+// Run SQL
+async function runQuery() {
+  const sql = sqlInput.value.trim();
+  if (!sql || !db) return;
+
+  const statements = sql.split(';').map(s => s.trim()).filter(s => {
+    // 过滤空语句和纯注释语句
+    if (s.length === 0) return false;
+    const nonComment = s.split('\n').filter(l => !l.trimStart().startsWith('--')).join('\n').trim();
+    return nonComment.length > 0;
+  });
+
+  try {
+    const allResults = [];
+    for (const stmt of statements) {
+      const result = await db.query(stmt);
+      // 深拷贝查询结果，防止后续语句通过引用修改已保存的结果
+      const resultCopy = Array.isArray(result) ? result.map(r => ({ ...r })) : result;
+      allResults.push({ sql: stmt, result: resultCopy });
+    }
+
+    if (allResults.length === 1) {
+      renderResult(allResults[0]);
+    } else {
+      renderAllResults(allResults);
+    }
+  } catch (e) {
+    renderError(e.message || String(e));
+  }
+}
+
+function renderResult({ sql, result }) {
+  if (Array.isArray(result)) {
+    renderTable(result);
+  } else {
+    renderSuccess(`✅ 执行成功 (影响 ${result ?? 0} 行)`);
+  }
+}
+
+function renderAllResults(allResults) {
+  let html = '';
+  for (const { sql, result } of allResults) {
+    html += `<div class="sql-tag">> ${escapeHTML(sql)}</div>`;
+    if (Array.isArray(result)) {
+      if (result.length === 0) {
+        html += '<div class="success-box">✅ 查询返回 0 行</div>';
+      } else {
+        html += buildTableHTML(result);
+      }
+    } else {
+      html += `<div class="success-box">✅ 执行成功 (影响 ${result ?? 0} 行)</div>`;
+    }
+    html += '<div style="height:12px"></div>';
+  }
+  resultArea.innerHTML = html;
+  updateRowCount(allResults.reduce((sum, r) => sum + (Array.isArray(r.result) ? r.result.length : 0), 0));
+}
+
+function renderTable(rows) {
+  if (!rows || rows.length === 0) {
+    resultArea.innerHTML = '<div class="success-box">✅ 查询返回 0 行</div>';
+    updateRowCount(0);
+    return;
+  }
+  resultArea.innerHTML = buildTableHTML(rows);
+  updateRowCount(rows.length);
+}
+
+function buildTableHTML(rows) {
+  const columns = Object.keys(rows[0]);
+  let html = '<table class="result-table"><thead><tr>';
+  for (const col of columns) {
+    html += `<th>${escapeHTML(col)}</th>`;
+  }
+  html += '</tr></thead><tbody>';
+  for (const row of rows) {
+    html += '<tr>';
+    for (const col of columns) {
+      const val = row[col];
+      html += `<td>${formatCell(val)}</td>`;
+    }
+    html += '</tr>';
+  }
+  html += '</tbody></table>';
+  return html;
+}
+
+function formatCell(val) {
+  if (val === null) return '<span style="color:#64748b;font-style:italic">NULL</span>';
+  if (val === undefined) return '<span style="color:#64748b">-</span>';
+  if (typeof val === 'boolean') return `<span style="color:#fbbf24">${val}</span>`;
+  if (typeof val === 'number') return `<span style="color:#fbbf24">${val}</span>`;
+  return escapeHTML(String(val));
+}
+
+function renderError(msg) {
+  resultArea.innerHTML = `<div class="error-box">❌ ${escapeHTML(msg)}</div>`;
+  updateRowCount(0);
+}
+
+function renderSuccess(msg) {
+  resultArea.innerHTML = `<div class="success-box">${msg}</div>`;
+}
+
+function renderInfo(msg) {
+  resultArea.innerHTML = `<div class="success-box" style="color:#22c55e;border-color:#22c55e;">${msg}</div>`;
+}
+
+function clearResults() {
+  resultArea.innerHTML = `<div class="empty-state"><div class="icon">⚡</div><div>结果已清空</div></div>`;
+  updateRowCount(0);
+}
+
+function updateRowCount(n) { rowCount.textContent = `${n} 行`; }
+function escapeHTML(str) { return String(str).replace(/&/g,'&amp;').replace(/</g,'&lt;').replace(/>/g,'&gt;').replace(/"/g,'&quot;').replace(/'/g,'&#039;'); }
+
+// Presets
+const presets = {
+  all: `-- 查看所有数据
+SELECT * FROM users;
+
+SELECT * FROM orders;
+
+SELECT * FROM products;`,
+  join: `-- INNER JOIN：用户 + 订单
+SELECT u.name, o.product, o.amount, o.quantity
+FROM users u
+INNER JOIN orders o ON u.id = o.user_id
+ORDER BY o.amount DESC;
+
+-- LEFT JOIN：包含没有订单的用户
+SELECT u.name, o.product, o.amount
+FROM users u
+LEFT JOIN orders o ON u.id = o.user_id;`,
+  agg: `-- 聚合统计：每个用户的消费
+SELECT u.name, COUNT(*) as orders, SUM(o.amount) as total_spent
+FROM users u
+INNER JOIN orders o ON u.id = o.user_id
+GROUP BY u.name
+ORDER BY total_spent DESC;
+
+-- 全局聚合
+SELECT COUNT(*) as total_users, AVG(age) as avg_age,
+       MIN(age) as min_age, MAX(age) as max_age
+FROM users;
+
+-- 分类统计
+SELECT category, COUNT(*) as product_count, AVG(price) as avg_price
+FROM products
+GROUP BY category;`,
+  ddl: `-- 查看所有表
+-- (使用 db.getTableNames() 替代)
+
+-- 创建新表
+CREATE TABLE tasks (
+  id STRING PRIMARY KEY,
+  title STRING NOT NULL,
+  done BOOLEAN DEFAULT false,
+  priority NUMBER DEFAULT 0
+);
+
+-- 插入数据
+INSERT INTO tasks (id, title, done, priority) VALUES ('t1', 'Learn SQLark', false, 1);
+INSERT INTO tasks VALUES ('t2', 'Write docs', true, 2);
+
+-- 查询
+SELECT * FROM tasks ORDER BY priority DESC;
+
+-- 删除表
+DROP TABLE tasks;`,
+  crud: `-- 增
+INSERT INTO users VALUES ('9', 'Frank', 'frank@demo.com', 40);
+
+-- 查
+SELECT * FROM users WHERE name = 'Frank';
+
+-- 改
+UPDATE users SET age = 41, email = 'frank2@demo.com' WHERE id = '9';
+
+-- 查（确认）
+SELECT * FROM users WHERE id = '9';
+
+-- 删
+DELETE FROM users WHERE id = '9';
+
+-- 确认
+SELECT COUNT(*) as user_count FROM users;`,
+  subquery: `-- IN 子查询：有订单的用户
+SELECT name, email FROM users
+WHERE id IN (SELECT user_id FROM orders);
+
+-- NOT IN 子查询：没有订单的用户
+SELECT name, email FROM users
+WHERE id NOT IN (SELECT user_id FROM orders);
+
+-- 标量子查询：消费最高的用户
+SELECT name, age FROM users
+WHERE id IN (
+  SELECT user_id FROM orders
+  WHERE amount = (SELECT MAX(amount) FROM orders)
+);`,
+  tx: `-- 事务演示：使用 db.transaction() API
+-- 查询用户 Alice
+SELECT * FROM users WHERE id = '1';
+
+-- 为 Alice 插入新订单
+INSERT INTO orders VALUES ('o99', '1', 'Headphones', 199, 1);
+
+-- 查看 Alice 的订单汇总
+SELECT u.name, COUNT(*) as order_count, SUM(o.amount) as total
+FROM users u INNER JOIN orders o ON u.id = o.user_id
+WHERE u.id = '1'
+GROUP BY u.name;
+
+-- 生产环境用 db.transaction() 包裹保证原子性`,
+  scalar: `-- 聚合无 GROUP BY 返回单行
+SELECT COUNT(*) as total_users, AVG(age) as avg_age FROM users;
+
+-- 年龄大于平均值的用户
+SELECT name, age FROM users
+WHERE age > (SELECT AVG(age) FROM users);
+
+-- 消费超过平均值的用户
+SELECT u.name, SUM(o.amount) as spent
+FROM users u INNER JOIN orders o ON u.id = o.user_id
+GROUP BY u.name
+HAVING SUM(o.amount) > (SELECT AVG(amount) FROM orders);`,
+  cascade: `-- 外键级联：重建 orders 表带 CASCADE
+DROP TABLE IF EXISTS orders;
+
+CREATE TABLE orders (
+  id STRING PRIMARY KEY,
+  user_id STRING REFERENCES users(id) ON DELETE CASCADE,
+  product STRING,
+  amount NUMBER,
+  quantity NUMBER DEFAULT 1
+);
+
+-- 重新插入数据
+INSERT INTO orders VALUES ('o1', '1', 'Laptop', 1200, 1);
+INSERT INTO orders VALUES ('o2', '1', 'Mouse', 50, 2);
+INSERT INTO orders VALUES ('o3', '2', 'Keyboard', 150, 1);
+
+-- 查看关联数据
+SELECT u.name, o.product, o.amount
+FROM users u INNER JOIN orders o ON u.id = o.user_id;
+
+-- 删除 Alice (id=1) 订单自动级联删除
+DELETE FROM users WHERE id = '1';
+
+-- 确认级联结果
+SELECT u.name, o.product, o.amount
+FROM users u LEFT JOIN orders o ON u.id = o.user_id;`,
+	  adv: `-- BETWEEN 范围查询
+SELECT * FROM users
+WHERE age BETWEEN 20 AND 30 AND name != 'Bob'
+ORDER BY age DESC;
+
+-- DISTINCT 去重
+SELECT DISTINCT age FROM users ORDER BY age;
+
+-- 多表 JOIN + 过滤 + 排序 + 分页
+SELECT u.name, o.product, o.amount
+FROM users u
+INNER JOIN orders o ON u.id = o.user_id
+WHERE o.amount >= 50
+ORDER BY o.amount DESC
+LIMIT 5 OFFSET 0;
+
+-- NOT LIKE 模糊排除
+	SELECT * FROM users
+	WHERE name NOT LIKE 'A%' AND age > 20;`,
+  alter: `-- 🏗 ALTER TABLE 动态修改表结构 (v0.2.5)
+
+-- 添加新列
+ALTER TABLE users ADD COLUMN phone STRING;
+
+-- 插入数据（含新列）
+INSERT INTO users (id, name, age, phone) VALUES ('6', 'Frank', 33, '123-4567');
+
+-- 查询确认
+SELECT * FROM users WHERE id = '6';
+
+-- 删除列
+ALTER TABLE users DROP COLUMN phone;
+
+-- 查询确认（phone 列已删除）
+SELECT * FROM users WHERE id = '6';`,
+  truncate: `-- 🗑 TRUNCATE TABLE 快速清空 (v0.2.5)
+
+-- 创建临时表并插入数据
+CREATE TABLE IF NOT EXISTS temp_logs (
+  id STRING PRIMARY KEY,
+  message STRING NOT NULL
+);
+INSERT INTO temp_logs VALUES ('1', 'log A');
+INSERT INTO temp_logs VALUES ('2', 'log B');
+INSERT INTO temp_logs VALUES ('3', 'log C');
+
+-- 确认数据
+SELECT COUNT(*) as total FROM temp_logs;
+
+-- TRUNCATE 快速清空
+TRUNCATE TABLE temp_logs;
+
+-- 确认清空
+SELECT COUNT(*) as total FROM temp_logs;
+
+-- 清理
+DROP TABLE temp_logs;`,
+	  aria: `-- 🌲 AriaEngine 演示 (v0.4.1)
+	-- 点击右上角「🌲 Aria」按钮切换数据库引擎到 AriaEngine
+	-- 当前数据库即运行在 Aria 引擎上（LSM-Tree · WAL 崩溃恢复 · MVCC · BloomFilter）
+	-- 基础 CRUD 与 Memory 引擎完全兼容
+	
+	-- 当前引擎确认
+	-- (内存中 Aria 引擎实例，数据经 WAL + SSTable 持久化到 IndexedDB)
+	CREATE TABLE IF NOT EXISTS tasks (
+	  id STRING PRIMARY KEY,
+	  title STRING NOT NULL,
+	  done BOOLEAN DEFAULT false
+	);
+	
+	-- 插入数据
+	INSERT INTO tasks VALUES ('t1', 'Implement AriaEngine', false);
+	INSERT INTO tasks VALUES ('t2', 'Write tests', false);
+	INSERT INTO tasks VALUES ('t3', 'Update docs', true);
+	
+	-- 查询
+	SELECT * FROM tasks ORDER BY title;
+	
+	-- 聚合统计
+	SELECT done, COUNT(*) as cnt FROM tasks GROUP BY done;
+	
+	-- CASE WHEN 表达式
+	SELECT title,
+	  CASE WHEN done THEN '✅ done' ELSE '⏳ pending' END AS status
+	FROM tasks;
+	
+	-- EXISTS 关联子查询
+	SELECT u.name FROM users u
+	WHERE EXISTS (SELECT 1 FROM orders o WHERE o.user_id = u.id);
+	
+	-- AriaEngine 特性:
+	-- • LSM-Tree: MemTable (红黑树) → SSTable 多级索引
+	-- • WAL: Write-Ahead Log 保证崩溃恢复 + 批量组提交
+	-- • MVCC: 版本链 + 快照隔离
+	-- • Buffer Pool: SSTable LRU 缓存 (256页 ~ 1MB) ✅ 已生效
+	-- • Bloom Filter: FNV-1a + Murmur 双哈希
+	-- • 二级索引: 每列独立 LSM + 动态 CREATE INDEX
+	-- • 外键级联: CASCADE / SET NULL / RESTRICT (v0.4.1)
+	
+	-- 生产环境 API（与演示页右上角切换等价）
+	-- const db = await MetonaSqlark.create({
+	--   name: 'my-app', mode: 'aria'
+	-- });`,
+	casewhen: `-- 🎯 CASE WHEN 条件表达式 (v0.3.1 / v0.3.2)
+
+-- SELECT 列：多 WHEN + ELSE
+SELECT name, age,
+  CASE WHEN age >= 30 THEN 'senior'
+       WHEN age >= 25 THEN 'mid'
+       ELSE 'junior' END AS age_group
+FROM users ORDER BY age;
+
+-- WHERE 条件中的 CASE WHEN
+SELECT name FROM users
+WHERE CASE WHEN age >= 25 THEN 'adult' ELSE 'young' END = 'adult';
+
+-- 聚合中的 CASE WHEN
+SELECT
+  SUM(CASE WHEN age >= 30 THEN 1 ELSE 0 END) AS seniors,
+  SUM(CASE WHEN age < 30 THEN 1 ELSE 0 END) AS juniors,
+  AVG(CASE WHEN age >= 25 THEN age END) AS avg_adult_age
+FROM users;`,
+	union: `-- 🔀 UNION / UNION ALL (v0.3.0)
+
+-- UNION 去重合并两表数据
+SELECT name FROM users WHERE age >= 30
+UNION
+SELECT name FROM users WHERE age < 30;
+
+-- UNION 对重复行去重（同查询两次 → 结果去重）
+SELECT category FROM products
+UNION
+SELECT category FROM products;
+
+-- UNION ALL 保留重复
+SELECT category FROM products WHERE price >= 100
+UNION ALL
+SELECT category FROM products WHERE price >= 50;`,
+	insertselect: `-- 📥 INSERT INTO ... SELECT (v0.3.0)
+
+-- 建备份表并复制全量数据
+DROP TABLE IF EXISTS users_backup;
+CREATE TABLE users_backup (
+  id STRING PRIMARY KEY, name STRING, email STRING, age NUMBER
+);
+INSERT INTO users_backup SELECT * FROM users;
+
+-- 确认复制
+SELECT COUNT(*) as backed_up FROM users_backup;
+
+-- INSERT SELECT 带 WHERE 过滤
+DROP TABLE IF EXISTS big_spenders;
+CREATE TABLE big_spenders (
+  id STRING PRIMARY KEY, product STRING, amount NUMBER
+);
+INSERT INTO big_spenders (id, product, amount)
+SELECT o.id, o.product, o.amount FROM orders o WHERE o.amount >= 150;
+
+-- 确认过滤结果
+SELECT * FROM big_spenders;`,
+	exists: `-- 🔍 EXISTS 关联子查询 (v0.3.0 / v0.3.1)
+
+-- 有订单的用户（关联子查询）
+SELECT u.name FROM users u
+WHERE EXISTS (SELECT 1 FROM orders o WHERE o.user_id = u.id);
+
+-- 无订单的用户（NOT EXISTS）
+SELECT u.name FROM users u
+WHERE NOT EXISTS (SELECT 1 FROM orders o WHERE o.user_id = u.id);
+
+-- EXISTS + JOIN 组合
+SELECT u.name, o.product, o.amount FROM users u
+JOIN orders o ON u.id = o.user_id
+WHERE EXISTS (SELECT 1 FROM orders o2 WHERE o2.user_id = u.id AND o2.amount > 100);`,
+	index: `-- 🗂 动态索引 CREATE / DROP INDEX (v0.3.0)
+
+-- 为 orders.user_id 创建索引（已有数据自动回填）
+CREATE INDEX idx_orders_user ON orders (user_id);
+
+-- 索引查找（v0.4.1: JOIN 主表 WHERE 条件下推到引擎，真正走二级索引）
+SELECT u.name, o.product, o.amount
+FROM orders o JOIN users u ON u.id = o.user_id
+WHERE o.user_id = '1';
+
+-- 删除索引
+DROP INDEX idx_orders_user ON orders (user_id);
+
+-- 删除后回退全表扫描（结果不变）
+SELECT * FROM orders WHERE user_id = '3';
+
+-- DROP 不存在的索引会报错（INDEX_NOT_FOUND）
+-- DROP INDEX idx_nonexist ON orders (user_id);`,
+	multistmt: `-- 📜 多语句 + 事务语句 (v0.3.0)
+
+-- 分号分隔的多语句一次执行
+DROP TABLE IF EXISTS audit;
+CREATE TABLE audit (id STRING PRIMARY KEY, msg STRING);
+INSERT INTO audit VALUES ('a1', 'first');
+INSERT INTO audit VALUES ('a2', 'second');
+SELECT * FROM audit ORDER BY id;
+
+-- 事务语句：BEGIN → ROLLBACK（a3 不会生效）
+BEGIN;
+INSERT INTO audit VALUES ('a3', 'will be rolled back');
+ROLLBACK;
+SELECT * FROM audit ORDER BY id;
+
+-- 事务语句：BEGIN → COMMIT（a4 生效）
+BEGIN;
+INSERT INTO audit VALUES ('a4', 'will be committed');
+COMMIT;
+SELECT COUNT(*) as total FROM audit;`,
+	v040: `-- 🚰 v0.4.0 新特性
+
+-- 派生表：FROM (SELECT ...) 子查询作为行源
+SELECT category, total FROM (
+  SELECT category, SUM(price) AS total FROM products GROUP BY category
+) AS t WHERE total > 100 ORDER BY total DESC;
+
+-- COUNT(DISTINCT col)：去重计数
+SELECT COUNT(DISTINCT category) AS categories FROM products;
+
+-- NULLS FIRST / LAST：NULL 排序位置控制
+SELECT name FROM users ORDER BY age ASC NULLS FIRST LIMIT 3;
+
+-- 普通列别名 + ORDER BY 别名
+SELECT name AS n FROM users ORDER BY n DESC;
+
+-- SQL 标准 '' 字符串转义
+SELECT 'it''s a test' AS escaped;
+
+-- 哈希连接（等值 ON 走 O(N+M)；多列等值 ON 同样支持）
+SELECT u.name, o.product FROM users u
+INNER JOIN orders o ON o.user_id = u.id;`,
+	};
+
+// v0.4.1: 点击预设前自动重置数据（前序预设可能修改/删除种子数据，重置保证每个预设可预期演示）
+async function loadPreset(name) {
+  if (presets[name]) {
+    sqlInput.value = presets[name];
+    await initDB();
+    runQuery();
+  }
+}
+
+// Keyboard shortcut
+document.addEventListener('keydown', e => {
+  if ((e.ctrlKey || e.metaKey) && e.key === 'Enter') {
+    e.preventDefault();
+    runQuery();
+  }
+});
+
+	// Boot
+	document.getElementById('btn-memory').style.opacity = '1';
+	document.getElementById('btn-aria').style.opacity = '0.6';
+	document.getElementById('engine-status').textContent = '⚡ Memory';
+	initDB().then(() => {
+	  console.log('✅ MetonaSqlark v0.4.1 demo ready');
+	  setTimeout(runQuery, 300);
+	}).catch(err => {
+	  renderError('初始化失败: ' + err.message);
+	});
+</script>
+</body>
+</html>