diff --git a/lib/db/migrations/001_initial.sql b/lib/db/migrations/001_initial.sql
new file mode 100644
index 0000000..a680f91
--- /dev/null
+++ b/lib/db/migrations/001_initial.sql
@@ -0,0 +1,257 @@
+-- 001_initial.sql
+-- シンプルグループウェア 初期スキーマ
+-- 全16テーブル + インデックス
+
+-- 1. users: システム利用ユーザー
+CREATE TABLE users (
+  id INTEGER PRIMARY KEY AUTOINCREMENT,
+  name TEXT NOT NULL,
+  email TEXT NOT NULL UNIQUE,
+  password_hash TEXT,
+  avatar_url TEXT,
+  role TEXT NOT NULL DEFAULT 'member',
+  status TEXT NOT NULL DEFAULT 'active',
+  created_at TEXT NOT NULL,
+  updated_at TEXT NOT NULL
+);
+
+-- 2. projects: プロジェクト
+CREATE TABLE projects (
+  id INTEGER PRIMARY KEY AUTOINCREMENT,
+  name TEXT NOT NULL,
+  description TEXT,
+  status TEXT NOT NULL DEFAULT 'active',
+  owner_id INTEGER NOT NULL,
+  created_at TEXT NOT NULL,
+  updated_at TEXT NOT NULL,
+  FOREIGN KEY (owner_id) REFERENCES users(id)
+);
+
+-- 3. project_members: プロジェクトメンバー
+CREATE TABLE project_members (
+  id INTEGER PRIMARY KEY AUTOINCREMENT,
+  project_id INTEGER NOT NULL,
+  user_id INTEGER NOT NULL,
+  role TEXT NOT NULL DEFAULT 'member',
+  joined_at TEXT NOT NULL,
+  UNIQUE(project_id, user_id),
+  FOREIGN KEY (project_id) REFERENCES projects(id) ON DELETE CASCADE,
+  FOREIGN KEY (user_id) REFERENCES users(id) ON DELETE CASCADE
+);
+
+-- 4. board_threads: 掲示板スレッド
+CREATE TABLE board_threads (
+  id INTEGER PRIMARY KEY AUTOINCREMENT,
+  project_id INTEGER NOT NULL,
+  title TEXT NOT NULL,
+  body_md TEXT NOT NULL,
+  author_id INTEGER NOT NULL,
+  category TEXT,
+  is_pinned INTEGER NOT NULL DEFAULT 0,
+  is_important INTEGER NOT NULL DEFAULT 0,
+  created_at TEXT NOT NULL,
+  updated_at TEXT NOT NULL,
+  deleted_at TEXT,
+  FOREIGN KEY (project_id) REFERENCES projects(id) ON DELETE CASCADE,
+  FOREIGN KEY (author_id) REFERENCES users(id)
+);
+
+-- 5. board_comments: 掲示板コメント
+CREATE TABLE board_comments (
+  id INTEGER PRIMARY KEY AUTOINCREMENT,
+  thread_id INTEGER NOT NULL,
+  author_id INTEGER NOT NULL,
+  body_md TEXT NOT NULL,
+  created_at TEXT NOT NULL,
+  updated_at TEXT NOT NULL,
+  deleted_at TEXT,
+  FOREIGN KEY (thread_id) REFERENCES board_threads(id) ON DELETE CASCADE,
+  FOREIGN KEY (author_id) REFERENCES users(id)
+);
+
+-- 6. chat_messages: チャットメッセージ
+CREATE TABLE chat_messages (
+  id INTEGER PRIMARY KEY AUTOINCREMENT,
+  project_id INTEGER NOT NULL,
+  author_id INTEGER NOT NULL,
+  body TEXT NOT NULL,
+  created_at TEXT NOT NULL,
+  updated_at TEXT NOT NULL,
+  deleted_at TEXT,
+  FOREIGN KEY (project_id) REFERENCES projects(id) ON DELETE CASCADE,
+  FOREIGN KEY (author_id) REFERENCES users(id)
+);
+
+-- 7. todo_columns: ToDoカラム
+CREATE TABLE todo_columns (
+  id INTEGER PRIMARY KEY AUTOINCREMENT,
+  project_id INTEGER NOT NULL,
+  name TEXT NOT NULL,
+  order_index INTEGER NOT NULL DEFAULT 0,
+  created_at TEXT NOT NULL,
+  updated_at TEXT NOT NULL,
+  FOREIGN KEY (project_id) REFERENCES projects(id) ON DELETE CASCADE
+);
+
+-- 8. todo_items: ToDoタスク
+CREATE TABLE todo_items (
+  id INTEGER PRIMARY KEY AUTOINCREMENT,
+  project_id INTEGER NOT NULL,
+  column_id INTEGER NOT NULL,
+  title TEXT NOT NULL,
+  description TEXT,
+  assignee_id INTEGER,
+  creator_id INTEGER NOT NULL,
+  priority TEXT NOT NULL DEFAULT 'normal',
+  start_date TEXT,
+  due_date TEXT,
+  completed_at TEXT,
+  order_index INTEGER NOT NULL DEFAULT 0,
+  milestone_id INTEGER,
+  created_at TEXT NOT NULL,
+  updated_at TEXT NOT NULL,
+  deleted_at TEXT,
+  FOREIGN KEY (project_id) REFERENCES projects(id) ON DELETE CASCADE,
+  FOREIGN KEY (column_id) REFERENCES todo_columns(id) ON DELETE CASCADE,
+  FOREIGN KEY (assignee_id) REFERENCES users(id),
+  FOREIGN KEY (creator_id) REFERENCES users(id)
+);
+
+-- 9. file_assets: ファイルアセット
+CREATE TABLE file_assets (
+  id INTEGER PRIMARY KEY AUTOINCREMENT,
+  project_id INTEGER NOT NULL,
+  uploader_id INTEGER NOT NULL,
+  filename TEXT NOT NULL,
+  original_name TEXT NOT NULL,
+  mime_type TEXT NOT NULL,
+  size INTEGER NOT NULL,
+  path TEXT NOT NULL,
+  created_at TEXT NOT NULL,
+  deleted_at TEXT,
+  FOREIGN KEY (project_id) REFERENCES projects(id) ON DELETE CASCADE,
+  FOREIGN KEY (uploader_id) REFERENCES users(id)
+);
+
+-- 10. project_notes: Markdownメモ
+CREATE TABLE project_notes (
+  id INTEGER PRIMARY KEY AUTOINCREMENT,
+  project_id INTEGER NOT NULL,
+  title TEXT NOT NULL,
+  body_md TEXT NOT NULL,
+  tags TEXT,
+  is_pinned INTEGER NOT NULL DEFAULT 0,
+  created_by_id INTEGER NOT NULL,
+  updated_by_id INTEGER NOT NULL,
+  created_at TEXT NOT NULL,
+  updated_at TEXT NOT NULL,
+  deleted_at TEXT,
+  FOREIGN KEY (project_id) REFERENCES projects(id) ON DELETE CASCADE,
+  FOREIGN KEY (created_by_id) REFERENCES users(id),
+  FOREIGN KEY (updated_by_id) REFERENCES users(id)
+);
+
+CREATE INDEX idx_project_notes_project_id ON project_notes(project_id);
+CREATE INDEX idx_project_notes_updated_at ON project_notes(updated_at);
+
+-- 11. milestones: マイルストーン
+CREATE TABLE milestones (
+  id INTEGER PRIMARY KEY AUTOINCREMENT,
+  project_id INTEGER NOT NULL,
+  title TEXT NOT NULL,
+  description TEXT,
+  due_date TEXT,
+  status TEXT NOT NULL DEFAULT 'open',
+  created_at TEXT NOT NULL,
+  updated_at TEXT NOT NULL,
+  deleted_at TEXT,
+  FOREIGN KEY (project_id) REFERENCES projects(id) ON DELETE CASCADE
+);
+
+-- 12. calendar_events: カレンダーイベント
+CREATE TABLE calendar_events (
+  id INTEGER PRIMARY KEY AUTOINCREMENT,
+  project_id INTEGER NOT NULL,
+  title TEXT NOT NULL,
+  description TEXT,
+  type TEXT NOT NULL,
+  start_at TEXT NOT NULL,
+  end_at TEXT,
+  created_by_id INTEGER NOT NULL,
+  related_todo_id INTEGER,
+  related_milestone_id INTEGER,
+  related_meeting_id INTEGER,
+  created_at TEXT NOT NULL,
+  updated_at TEXT NOT NULL,
+  deleted_at TEXT,
+  FOREIGN KEY (project_id) REFERENCES projects(id) ON DELETE CASCADE,
+  FOREIGN KEY (created_by_id) REFERENCES users(id)
+);
+
+-- 13. meetings: ミーティング
+CREATE TABLE meetings (
+  id INTEGER PRIMARY KEY AUTOINCREMENT,
+  project_id INTEGER NOT NULL,
+  title TEXT NOT NULL,
+  description TEXT,
+  location TEXT,
+  meeting_url TEXT,
+  start_at TEXT NOT NULL,
+  end_at TEXT NOT NULL,
+  agenda_md TEXT,
+  minutes_md TEXT,
+  created_by_id INTEGER NOT NULL,
+  created_at TEXT NOT NULL,
+  updated_at TEXT NOT NULL,
+  deleted_at TEXT,
+  FOREIGN KEY (project_id) REFERENCES projects(id) ON DELETE CASCADE,
+  FOREIGN KEY (created_by_id) REFERENCES users(id)
+);
+
+-- 14. meeting_members: ミーティング参加メンバー
+CREATE TABLE meeting_members (
+  id INTEGER PRIMARY KEY AUTOINCREMENT,
+  meeting_id INTEGER NOT NULL,
+  user_id INTEGER NOT NULL,
+  status TEXT NOT NULL DEFAULT 'invited',
+  UNIQUE(meeting_id, user_id),
+  FOREIGN KEY (meeting_id) REFERENCES meetings(id) ON DELETE CASCADE,
+  FOREIGN KEY (user_id) REFERENCES users(id)
+);
+
+-- 15. notifications: 通知
+CREATE TABLE notifications (
+  id INTEGER PRIMARY KEY AUTOINCREMENT,
+  user_id INTEGER NOT NULL,
+  project_id INTEGER,
+  type TEXT NOT NULL,
+  title TEXT NOT NULL,
+  body TEXT,
+  read_at TEXT,
+  created_at TEXT NOT NULL,
+  FOREIGN KEY (user_id) REFERENCES users(id) ON DELETE CASCADE,
+  FOREIGN KEY (project_id) REFERENCES projects(id) ON DELETE CASCADE
+);
+
+-- 16. activity_logs: アクティビティログ
+CREATE TABLE activity_logs (
+  id INTEGER PRIMARY KEY AUTOINCREMENT,
+  project_id INTEGER NOT NULL,
+  actor_id INTEGER NOT NULL,
+  action TEXT NOT NULL,
+  target_type TEXT NOT NULL,
+  target_id INTEGER,
+  metadata_json TEXT,
+  created_at TEXT NOT NULL,
+  FOREIGN KEY (project_id) REFERENCES projects(id) ON DELETE CASCADE,
+  FOREIGN KEY (actor_id) REFERENCES users(id)
+);
+
+CREATE INDEX idx_activity_logs_project_id ON activity_logs(project_id);
+CREATE INDEX idx_activity_logs_created_at ON activity_logs(created_at);
+CREATE INDEX idx_notifications_user_id ON notifications(user_id);
+CREATE INDEX idx_chat_messages_project_id ON chat_messages(project_id);
+CREATE INDEX idx_board_threads_project_id ON board_threads(project_id);
+CREATE INDEX idx_todo_items_project_id ON todo_items(project_id);
+CREATE INDEX idx_meetings_project_id ON meetings(project_id);
+CREATE INDEX idx_calendar_events_project_id ON calendar_events(project_id);
diff --git a/lib/db/migrator.ts b/lib/db/migrator.ts
new file mode 100644
index 0000000..431d9f6
--- /dev/null
+++ b/lib/db/migrator.ts
@@ -0,0 +1,68 @@
+import fs from 'node:fs';
+import path from 'node:path';
+import { SqliteDatabase } from './sqlite';
+
+/**
+ * SQLファイルベースのMigration機構。
+ * - Migrationファイルをファイル名順に実行する
+ * - 実行済みファイルは再実行しない
+ * - 1ファイルごとにトランザクションを張り、失敗時はロールバックする
+ */
+export class Migrator {
+  constructor(
+    private readonly db: SqliteDatabase,
+    private readonly migrationsDir: string
+  ) {}
+
+  /**
+   * 未適用のMigrationをファイル名順に実行する
+   */
+  migrate(): void {
+    this.ensureMigrationsTable();
+
+    const applied = this.db.query<{ filename: string }>(
+      'SELECT filename FROM schema_migrations'
+    );
+    const appliedSet = new Set(applied.map((x) => x.filename));
+
+    const files = fs
+      .readdirSync(this.migrationsDir)
+      .filter((file) => file.endsWith('.sql'))
+      .sort();
+
+    for (const file of files) {
+      if (appliedSet.has(file)) continue;
+
+      const fullPath = path.join(this.migrationsDir, file);
+      const sql = fs.readFileSync(fullPath, 'utf-8');
+
+      this.db.transaction(() => {
+        this.db.execute(sql);
+        this.db.execute(
+          `INSERT INTO schema_migrations (filename, applied_at) VALUES (@filename, @appliedAt)`,
+          { filename: file, appliedAt: new Date().toISOString() }
+        );
+      });
+    }
+  }
+
+  /**
+   * 適用済みMigration一覧を取得する
+   */
+  getAppliedMigrations(): { filename: string; applied_at: string }[] {
+    this.ensureMigrationsTable();
+    return this.db.query<{ filename: string; applied_at: string }>(
+      'SELECT filename, applied_at FROM schema_migrations ORDER BY filename'
+    );
+  }
+
+  private ensureMigrationsTable(): void {
+    this.db.execute(`
+      CREATE TABLE IF NOT EXISTS schema_migrations (
+        id INTEGER PRIMARY KEY AUTOINCREMENT,
+        filename TEXT NOT NULL UNIQUE,
+        applied_at TEXT NOT NULL
+      )
+    `);
+  }
+}
diff --git a/lib/db/run-migrations.ts b/lib/db/run-migrations.ts
new file mode 100644
index 0000000..0475038
--- /dev/null
+++ b/lib/db/run-migrations.ts
@@ -0,0 +1,26 @@
+import path from 'node:path';
+import fs from 'node:fs';
+import { getDb, resetDbInstance } from './sqlite';
+import { Migrator } from './migrator';
+
+const migrationsDir = path.join(process.cwd(), 'lib', 'db', 'migrations');
+const dbPath = process.env.SQLITE_PATH ?? './data/app.db';
+
+const dbDir = path.dirname(dbPath);
+if (!fs.existsSync(dbDir)) {
+  fs.mkdirSync(dbDir, { recursive: true });
+}
+
+const db = getDb();
+const migrator = new Migrator(db, migrationsDir);
+
+migrator.migrate();
+
+const applied = migrator.getAppliedMigrations();
+console.log(`Migrations applied: ${applied.length}`);
+for (const m of applied) {
+  console.log(`  - ${m.filename} (applied at ${m.applied_at})`);
+}
+
+db.close();
+resetDbInstance();
diff --git a/lib/db/sqlite.ts b/lib/db/sqlite.ts
new file mode 100644
index 0000000..6f04bfa
--- /dev/null
+++ b/lib/db/sqlite.ts
@@ -0,0 +1,90 @@
+import Database from 'better-sqlite3';
+
+export type SqlParams = Record<string, unknown> | unknown[];
+
+export interface ExecuteResult {
+  changes: number;
+  lastInsertRowid: number | bigint;
+}
+
+/**
+ * SQLiteへのアクセスを一元管理する共通SQLラッパー。
+ * 各Repositoryは直接better-sqlite3を触らず、必ずこのクラスを通してSQLを実行する。
+ */
+export class SqliteDatabase {
+  private db: Database.Database;
+
+  constructor(dbPath: string) {
+    this.db = new Database(dbPath);
+
+    this.db.pragma('journal_mode = WAL');
+    this.db.pragma('foreign_keys = ON');
+  }
+
+  /**
+   * 複数行を取得するSELECT
+   */
+  query<T>(sql: string, params?: SqlParams): T[] {
+    return this.db.prepare(sql).all(params ?? {}) as T[];
+  }
+
+  /**
+   * 単一行を取得するSELECT（該当なしの場合はnull）
+   */
+  get<T>(sql: string, params?: SqlParams): T | null {
+    const row = this.db.prepare(sql).get(params ?? {}) as T | undefined;
+    return row ?? null;
+  }
+
+  /**
+   * INSERT / UPDATE / DELETEを実行する
+   */
+  execute(sql: string, params?: SqlParams): ExecuteResult {
+    const result = this.db.prepare(sql).run(params ?? {});
+
+    return {
+      changes: result.changes,
+      lastInsertRowid: result.lastInsertRowid,
+    };
+  }
+
+  /**
+   * トランザクション内でコールバックを実行する
+   */
+  transaction<T>(callback: () => T): T {
+    const tx = this.db.transaction(callback);
+    return tx();
+  }
+
+  /**
+   * DB接続を閉じる
+   */
+  close(): void {
+    this.db.close();
+  }
+}
+
+let instance: SqliteDatabase | null = null;
+
+/**
+ * シングルトンのDB接続を取得する。
+ * dbPathは process.env.SQLITE_PATH ?? "./data/app.db"
+ */
+export function getDb(): SqliteDatabase {
+  if (!instance) {
+    const dbPath = process.env.SQLITE_PATH ?? './data/app.db';
+    instance = new SqliteDatabase(dbPath);
+  }
+
+  return instance;
+}
+
+/**
+ * テスト用途: シングルトンインスタンスをリセットする
+ */
+export function resetDbInstance(): void {
+  if (instance) {
+    instance.close();
+    instance = null;
+  }
+}
diff --git a/lib/types/index.ts b/lib/types/index.ts
new file mode 100644
index 0000000..bff64f4
--- /dev/null
+++ b/lib/types/index.ts
@@ -0,0 +1,241 @@
+/**
+ * 全Entity型定義・共有型
+ * functional-design.md のデータモデルに対応。
+ * タイムスタンプはISO8601文字列(TEXT)。真偽値はINTEGER(0/1)。
+ */
+
+// ===== 列挙型 =====
+
+export type UserRole = 'system_admin' | 'project_admin' | 'member' | 'guest';
+export type UserStatus = 'active' | 'inactive';
+export type ProjectStatus = 'active' | 'on_hold' | 'completed' | 'archived';
+export type ProjectMemberRole = 'admin' | 'member' | 'guest';
+export type BoardCategory =
+  | 'notice'
+  | 'spec'
+  | 'minutes'
+  | 'question'
+  | 'decision'
+  | 'trouble'
+  | 'memo';
+export type TodoPriority = 'low' | 'normal' | 'high';
+export type MilestoneStatus = 'open' | 'closed';
+export type CalendarEventType =
+  | 'meeting'
+  | 'deadline'
+  | 'milestone'
+  | 'todo'
+  | 'reminder'
+  | 'custom';
+export type MeetingMemberStatus = 'invited' | 'accepted' | 'declined';
+export type NotificationType =
+  | 'mention'
+  | 'todo_assigned'
+  | 'todo_due_soon'
+  | 'meeting_invited'
+  | 'board_commented'
+  | 'project_added'
+  | 'file_shared'
+  | 'note_updated';
+
+// ===== エンティティ =====
+
+export interface User {
+  id: number;
+  name: string;
+  email: string;
+  passwordHash: string | null;
+  avatarUrl: string | null;
+  role: UserRole;
+  status: UserStatus;
+  createdAt: string;
+  updatedAt: string;
+}
+
+export interface Project {
+  id: number;
+  name: string;
+  description: string | null;
+  status: ProjectStatus;
+  ownerId: number;
+  createdAt: string;
+  updatedAt: string;
+}
+
+export interface ProjectMember {
+  id: number;
+  projectId: number;
+  userId: number;
+  role: ProjectMemberRole;
+  joinedAt: string;
+}
+
+export interface BoardThread {
+  id: number;
+  projectId: number;
+  title: string;
+  bodyMd: string;
+  authorId: number;
+  category: BoardCategory | null;
+  isPinned: number;
+  isImportant: number;
+  createdAt: string;
+  updatedAt: string;
+  deletedAt: string | null;
+}
+
+export interface BoardComment {
+  id: number;
+  threadId: number;
+  authorId: number;
+  bodyMd: string;
+  createdAt: string;
+  updatedAt: string;
+  deletedAt: string | null;
+}
+
+export interface ChatMessage {
+  id: number;
+  projectId: number;
+  authorId: number;
+  body: string;
+  createdAt: string;
+  updatedAt: string;
+  deletedAt: string | null;
+}
+
+export interface TodoColumn {
+  id: number;
+  projectId: number;
+  name: string;
+  orderIndex: number;
+  createdAt: string;
+  updatedAt: string;
+}
+
+export interface TodoItem {
+  id: number;
+  projectId: number;
+  columnId: number;
+  title: string;
+  description: string | null;
+  assigneeId: number | null;
+  creatorId: number;
+  priority: TodoPriority;
+  startDate: string | null;
+  dueDate: string | null;
+  completedAt: string | null;
+  orderIndex: number;
+  milestoneId: number | null;
+  createdAt: string;
+  updatedAt: string;
+  deletedAt: string | null;
+}
+
+export interface FileAsset {
+  id: number;
+  projectId: number;
+  uploaderId: number;
+  filename: string;
+  originalName: string;
+  mimeType: string;
+  size: number;
+  path: string;
+  createdAt: string;
+  deletedAt: string | null;
+}
+
+export interface ProjectNote {
+  id: number;
+  projectId: number;
+  title: string;
+  bodyMd: string;
+  tags: string | null;
+  isPinned: number;
+  createdById: number;
+  updatedById: number;
+  createdAt: string;
+  updatedAt: string;
+  deletedAt: string | null;
+}
+
+export interface Milestone {
+  id: number;
+  projectId: number;
+  title: string;
+  description: string | null;
+  dueDate: string | null;
+  status: MilestoneStatus;
+  createdAt: string;
+  updatedAt: string;
+  deletedAt: string | null;
+}
+
+export interface CalendarEvent {
+  id: number;
+  projectId: number;
+  title: string;
+  description: string | null;
+  type: CalendarEventType;
+  startAt: string;
+  endAt: string | null;
+  createdById: number;
+  relatedTodoId: number | null;
+  relatedMilestoneId: number | null;
+  relatedMeetingId: number | null;
+  createdAt: string;
+  updatedAt: string;
+  deletedAt: string | null;
+}
+
+export interface Meeting {
+  id: number;
+  projectId: number;
+  title: string;
+  description: string | null;
+  location: string | null;
+  meetingUrl: string | null;
+  startAt: string;
+  endAt: string;
+  agendaMd: string | null;
+  minutesMd: string | null;
+  createdById: number;
+  createdAt: string;
+  updatedAt: string;
+  deletedAt: string | null;
+}
+
+export interface MeetingMember {
+  id: number;
+  meetingId: number;
+  userId: number;
+  status: MeetingMemberStatus;
+}
+
+export interface Notification {
+  id: number;
+  userId: number;
+  projectId: number | null;
+  type: NotificationType;
+  title: string;
+  body: string | null;
+  readAt: string | null;
+  createdAt: string;
+}
+
+export interface ActivityLog {
+  id: number;
+  projectId: number;
+  actorId: number;
+  action: string;
+  targetType: string;
+  targetId: number | null;
+  metadataJson: string | null;
+  createdAt: string;
+}
+
+export interface SchemaMigration {
+  id: number;
+  filename: string;
+  appliedAt: string;
+}
diff --git a/tests/helpers/db.ts b/tests/helpers/db.ts
new file mode 100644
index 0000000..aa9eee9
--- /dev/null
+++ b/tests/helpers/db.ts
@@ -0,0 +1,46 @@
+import os from 'node:os';
+import fs from 'node:fs';
+import path from 'node:path';
+import { SqliteDatabase } from '@/lib/db/sqlite';
+
+let counter = 0;
+
+/**
+ * テスト用の一時SQLite DBを作成する。
+ * 実DB(一時ファイル)を使用し、テスト終了時に自動削除される。
+ */
+export function createTestDb(): SqliteDatabase {
+  const tmpDir = os.tmpdir();
+  const dbPath = path.join(
+    tmpDir,
+    `test-${process.pid}-${Date.now()}-${counter++}.db`
+  );
+  const db = new SqliteDatabase(dbPath);
+
+  const originalClose = db.close.bind(db);
+  db.close = () => {
+    originalClose();
+    if (fs.existsSync(dbPath)) {
+      fs.unlinkSync(dbPath);
+    }
+    const walPath = `${dbPath}-wal`;
+    const shmPath = `${dbPath}-shm`;
+    if (fs.existsSync(walPath)) fs.unlinkSync(walPath);
+    if (fs.existsSync(shmPath)) fs.unlinkSync(shmPath);
+  };
+
+  return db;
+}
+
+/**
+ * マイグレーション済みのテスト用DBを作成する
+ */
+export function createMigratedTestDb(): SqliteDatabase {
+  const db = createTestDb();
+  const migrationsDir = path.join(process.cwd(), 'lib', 'db', 'migrations');
+  // eslint-disable-next-line @typescript-eslint/no-require-imports
+  const { Migrator } = require('@/lib/db/migrator');
+  const migrator = new Migrator(db, migrationsDir);
+  migrator.migrate();
+  return db;
+}