英文:
Access PrismaClient instance in multiple files
问题
controllers/users.ts 文件中，您想要在多个文件中访问 PrismaClient 实例，可以通过以下方式解决：
首先，在 controllers/users.ts 文件的顶部，添加以下代码以引入 PrismaClient：
import { PrismaClient } from '@prisma/client';const prisma = new PrismaClient();
然后，您可以在 controllers/users.ts 文件的各个函数中使用 prisma 变量来访问 PrismaClient 实例，就像这样：
export const createUser: RequestHandler = async (req, res, next) => {try {const newUser = await prisma.user.create({data: {username: req.body.username,email: req.body.email,password: req.body.password,},});res.status(200).json(newUser);} catch (error) {next(error);}}export const getUsers: RequestHandler = async (req, res, next) => {try {const users = await prisma.user.findMany();res.status(200).json(users);} catch (error) {next(error);}}export const getUser: RequestHandler = async (req, res, next) => {try {const userId = parseInt(req.params.userId, 10);const user = await prisma.user.findUnique({where: {id: userId,},});if (!user) {return res.status(404).json({ error: 'User not found' });}res.status(200).json(user);} catch (error) {next(error);}}
这样，您可以在 controllers/users.ts 文件中的每个函数中共享同一个 PrismaClient 实例，而无需在每个函数中重新创建它。
英文:
I have a node.js/express app with the Prisma ORM. I would like to access my PrismaClient instance in multiple files, not just index.ts.
Tutorials I have seen all only access the PrismaClient instance inside index.ts, which makes that file bloated.
For example, I have folders for routes and controllers. I would like to access the PrismaClient in each of the files within the controllers folder.
Current code:
index.ts
import express from "express";import { PrismaClient } from '@prisma/client';import userRoutes from "./routes/users";const app = express();// best not to have multiple instances of PrismaClientexport const prisma = new PrismaClient();app.get("/", (req, res) => {res.send("helloBAA")})// routesapp.use('/api/users', userRoutes)app.listen(3500, () => {console.log("listening on port 3500")})
routes/users.ts
import { Router } from 'express';import { createUser, getUsers, getUser } from '../controllers/users';const router = Router();// whole route: /api/users...router.post('/create', createUser);router.get('/all', getUsers);router.get('/:userId', getUser);export default router;
controllers/users.ts
import { RequestHandler } from 'express';// import prisma from './index.ts';import dotenv from "dotenv"import axios from 'axios';export const createUser:RequestHandler = async (req, res, next) => {let newObj = {username: req.body.username,email: req.body.email,password: req.body.password}res.status(200).json({ "test": "createUser" });}export const getUsers: RequestHandler = async (req, res, next) => {res.status(200).json({ "test": "getUsers" });}export const getUser: RequestHandler = async (req, res, next) => {res.status(200).json({ "test": "getUser" });}
If I try to import prisma from index.ts into controllers/users.ts, I get errors. How should I fix this?
答案1
得分: 1
这是因为存在循环依赖，两个或更多模块直接或间接地相互依赖，形成一个循环。在一个单独的文件中创建一个 prismaClient 实例，并在需要时进行导入。像这样：我有一个 prismaClient.ts 文件
const { PrismaClient } = require("@prisma/client");const prismaInstance = new PrismaClient();module.exports = prismaInstance;
在 index.ts 中像这样导入该文件：
const prismaInstance = require("./prismaClient");export const prisma = prismaInstance;
从 index.ts 导入该文件到需要的文件中：
const prisma = require('./index');
英文:
This is because circular dependency where two or more modules depend on each other directly or indirectly, froming a loop.
Make the prismaClient instance in a separate file and import this whenever required.Like this:I have a prismaClient.ts file
const { PrismaClient } = require("@prisma/client");const prismaInstance = new PrismaClient();module.exports = prisma;
import the file in the index.ts like this:
const prismaInstance = require("./prismaClient");export const prisma = prismaInstance;
Import the file from index.ts to required files:
const prisma = require('./index');
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