使用 expressjs 和 prisma 根据请求源更改数据库

Question

I want to change database dynamically based on request origin.

I create a globalMiddleware which is called on every routes.

 // middlwares/global.middleware.js import DBController from "../controllers/db.controller.js"; import { db1, db2 } from "../prisma/prismaClient.js"; export default (req, res, next) => { const dbcontroller = DBController(); const domain = req.get("origin"); switch (domain) { case "http://localhost:3000": dbcontroller.setDB(db1); break; case "http://localhost:3001": dbcontroller.setDB(db2); break; } next(); };

but when i set the db inside DBController by calling dbcontroller.setDB() method and finally calling this.DB it is undefined.

 // controller/db.controller.js import autoBind from "auto-bind"; class DBController { constructor() { this.DB; autoBind(this); } setDB(prismaClient) { this.DB = prismaClient; } } export default DBController;

 // conrtoller/controller.js import { generateResponse } from "./../util/public.util.js"; import DBController from "./db.controller.js"; import autoBind from "auto-bind"; import createError from "http-errors"; class Controller extends DBController { constructor() { super(); this.generateResponse = generateResponse; this.createError = createError; autoBind(this); } } export default Controller;

 // controller/article.controller.js import Controller from "./controller.js"; class ArticleController extends Controller { async get(req, res, next) { try { const articles = await this.DB.article.findMany(); //this.DB is undefined const response = this.generateResponse("success", articles); res.send(response); } catch (error) { next(error); } } } export default new ArticleController();

I don't know how should i set a global DB inside a top-level controller which can be used every where.

I also try js global.db vars and express app.set("db",db1) but i think these are not a good solution for this work.

Answer 1

finally I modify global.middleware.js file and modify request instead of setting database in a high-level controller :

 import { prisma_aramgostar, prisma_karen } from "../prisma/prismaClient.js"; export default async(req, res, next) => { const domain = await req.get("x-forwarded-host"); switch (domain) { case "localhost:3000": req.DB = prisma_aramgostar; console.log("db: aramgostar"); break; case "127.0.0.1:3001": req.DB = prisma_karen; console.log("db: karen"); break; } next(); };