🗄️ Prisma ORM

// prisma/schema.prisma
generator client {
  provider = "prisma-client-js"
}
datasource db {
  provider = "sqlite"      // 开发用 SQLite，上线改 "postgresql"
  url      = env("DATABASE_URL")
}

model Product {
  id          String   @id @default(cuid())    // 自动生成唯一 ID
  name        String
  description String?
  price       Float
  imageUrl    String?
  stock       Int      @default(0)
  createdAt   DateTime @default(now())
  updatedAt   DateTime @updatedAt
}

model Order {
  id         String      @id @default(cuid())
  userId     String                        // 暂写死，以后接登录
  total      Float
  status     String      @default("pending")
  items      OrderItem[]
  createdAt  DateTime    @default(now())
}

model OrderItem {
  id        String   @id @default(cuid())
  orderId   String
  order     Order    @relation(fields: [orderId], references: [id])
  productId String
  product   Product  @relation(fields: [productId], references: [id])
  quantity  Int
  price     Float                         // 下单时价格快照
}

import { prisma } from '@/lib/prisma'

// 查列表（支持分页、排序、条件）
const products = await prisma.product.findMany({
  where: { price: { gte: 100 } },     // WHERE price >= 100
  orderBy: { createdAt: 'desc' },
  skip: 0, take: 10,
})

// 查单个
const product = await prisma.product.findUnique({ where: { id: 'xxx' } })

// 新增
const created = await prisma.product.create({
  data: { name: '商品名', price: 99.9, stock: 100 }
})

// 更新
const updated = await prisma.product.update({
  where: { id: 'xxx' },
  data: { price: 89.9 }
})

// 删除
await prisma.product.delete({ where: { id: 'xxx' } })

// 关联查询（联表查订单 + 商品）
const order = await prisma.order.findUnique({
  where: { id: 'xxx' },
  include: { items: { include: { product: true } } }
})