Sửa lỗi tái cấu trúc thư mục và khai báo import

backend/prisma/prisma.service.ts

@@ -0,0 +1,16 @@
+import { Injectable, OnModuleInit, OnModuleDestroy } from '@nestjs/common';
+import { PrismaClient } from '@prisma/client';
+import { PrismaPg } from '@prisma/adapter-pg';
+import { Pool } from 'pg';
+
+@Injectable()
+export class PrismaService extends PrismaClient implements OnModuleInit, OnModuleDestroy {
+  constructor() {
+    const pool = new Pool({ connectionString: process.env.DATABASE_URL });
+    const adapter = new PrismaPg(pool);
+    super({ adapter });
+  }
+
+  async onModuleInit() { await this.$connect(); }
+  async onModuleDestroy() { await this.$disconnect(); }
+}