🎉 init: 小龙的工作空间

.benchmark/petcare/fullstack/apps/api/src/db/client.ts

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+// SQLite database client (sql.js — pure WASM, no native deps)
+import initSqlJs, { type Database, type BindParams } from "sql.js";
+import { createTables } from "./schema.js";
+
+let db: Database | null = null;
+let initPromise: Promise<Database> | null = null;
+
+/** Initialize the database (call once at startup). */
+export async function initDb(dbPath?: string): Promise<Database> {
+  if (db) return db;
+  if (initPromise) return initPromise;
+
+  initPromise = (async () => {
+    const SQL = await initSqlJs();
+    const path = dbPath || process.env.DATABASE_URL || ":memory:";
+
+    // Try to load existing database from file
+    let buffer: ArrayLike<number> | undefined;
+    if (path !== ":memory:") {
+      try {
+        const fs = await import("node:fs/promises");
+        const data = await fs.readFile(path);
+        buffer = new Uint8Array(data);
+      } catch {
+        // File doesn't exist yet — start fresh
+      }
+    }
+
+    db = new SQL.Database(buffer);
+    db.run("PRAGMA foreign_keys = ON");
+    createTables(db);
+    return db;
+  })();
+
+  return initPromise;
+}
+
+/** Get the initialized database (must call initDb first). */
+export function getDb(): Database {
+  if (!db) throw new Error("Database not initialized. Call initDb() first.");
+  return db;
+}
+
+/** Save database to disk. */
+export async function saveDb(dbPath?: string): Promise<void> {
+  if (!db) return;
+  const path = dbPath || process.env.DATABASE_URL || "./data/app.db";
+  if (path === ":memory:") return;
+  const fs = await import("node:fs/promises");
+  const { dirname } = await import("node:path");
+  await fs.mkdir(dirname(path), { recursive: true });
+  const data = db.export();
+  await fs.writeFile(path, Buffer.from(data));
+}
+
+export async function closeDb(): Promise<void> {
+  if (db) {
+    await saveDb();
+    db.close();
+    db = null;
+    initPromise = null;
+  }
+}
+
+// Helper: run a query and return all rows as objects
+export function queryAll<T = Record<string, unknown>>(sql: string, params: BindParams = []): T[] {
+  const d = getDb();
+  const stmt = d.prepare(sql);
+  if (params) stmt.bind(params);
+  const results: T[] = [];
+  while (stmt.step()) {
+    const row = stmt.getAsObject();
+    results.push(row as unknown as T);
+  }
+  stmt.free();
+  return results;
+}
+
+// Helper: run a query and return the first row
+export function queryOne<T = Record<string, unknown>>(sql: string, params: BindParams = []): T | undefined {
+  const rows = queryAll<T>(sql, params);
+  return rows[0];
+}
+
+// Helper: run a mutation and return { changes, lastInsertRowid }
+export function execute(sql: string, params: BindParams = []): { changes: number; lastInsertRowid: number } {
+  const d = getDb();
+  d.run(sql, params);
+  return {
+    changes: d.getRowsModified(),
+    lastInsertRowid: 0,
+  };
+}