后端建立 TypeScript 构建链路

apps/backend/src/db/client.ts

@@ -0,0 +1,57 @@
+import { Pool } from 'pg'
+import type { PoolClient, QueryResult, QueryResultRow } from 'pg'
+
+import { runtimeConfig } from '../config/runtime.js'
+
+let poolInstance: Pool | null = null
+
+export function getDb(): Pool {
+  if (!poolInstance) {
+    poolInstance = new Pool({
+      connectionString: String(runtimeConfig.database?.url || '').trim(),
+      ssl: runtimeConfig.database?.ssl ? { rejectUnauthorized: false } : false,
+      max: Number(runtimeConfig.database?.maxConnections || 10),
+    })
+  }
+
+  return poolInstance
+}
+
+export async function query(text: string, params?: unknown[]): Promise<QueryResult<any>>
+export async function query<T extends QueryResultRow>(
+  text: string,
+  params?: unknown[],
+): Promise<QueryResult<T>>
+export async function query<T extends QueryResultRow>(
+  text: string,
+  params: unknown[] = [],
+): Promise<QueryResult<T>> {
+  const pool = getDb()
+  return pool.query<T>(text, params)
+}
+
+export async function withTransaction<T>(fn: (client: PoolClient) => Promise<T>): Promise<T> {
+  const client = await getDb().connect()
+
+  try {
+    await client.query('BEGIN')
+    const result = await fn(client)
+    await client.query('COMMIT')
+    return result
+  } catch (error) {
+    await client.query('ROLLBACK')
+    throw error
+  } finally {
+    client.release()
+  }
+}
+
+export async function closeDb(): Promise<void> {
+  if (!poolInstance) {
+    return
+  }
+
+  const pool = poolInstance
+  poolInstance = null
+  await pool.end()
+}