Setup backend DB and add example service

[Qrtn]

Status:

🚀 Ready

Description

Setup backend DB and add example service.

• Add script for creating Postgres role, databases, and seeding with data
• Update README with DB setup info
• Add example service for accessing DB
• Add example route that uses this service

Example route /students/{id} works for testing DB.

Why a service layer

• Avoid writing SQL queries in the routes
• Separation of business logic from HTTP route logic
• If method of accessing data changes, we can just update the services, w/o touching the routes
• Possible to unit test services only, rather than whole route

Workflow for service layer

• When implementing a new api method, add a new "service" in ../services/MODULE.js
• Then add a new route in ../routes/MODULE.js
• Each route imports the service functions it needs from ../services/MODULE.js
• Think about how to generalize "services" into reusable methods, rather than being specifically for 1 route (although that's ok too)

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[yousefa00]

Amazing, left some small comments 🚀

[yousefa00]

Very nitpicky, but do you think we should reorder these imports, moving router under express and the two others immediately below and without a new line between them?

[Qrtn]

Fixed! In general, I think it's still a good idea to separate third-party requires and internal requires with a blank line, though. So we can differentiate them at a glance. I pushed a new commit as an example.

[Qrtn]

const express = require("express");
const router = express.Router();
const statusCodes = require("http-status-codes");

const { getStudentById } = require("../services/student.js");

[yousefa00]

Yep we should do this instead, thanks for pointing that out :)

[yousefa00]

Status:

🚀 Ready

Description

Setup backend DB and add example service.

• Add script for creating Postgres role, databases, and seeding with data
• Update README with DB setup info
• Add example service for accessing DB
• Add example route that uses this service

Example route /students/{id} works for testing DB.

Why a service layer

• Avoid writing SQL queries in the routes
• Separation of business logic from HTTP route logic
• If method of accessing data changes, we can just update the services, w/o touching the routes
• Possible to unit test services only, rather than whole route

Workflow for service layer

• When implementing a new api method, add a new "service" in ../services/MODULE.js
• Then add a new route in ../routes/MODULE.js
• Each route imports the service functions it needs from ../services/MODULE.js
• Think about how to generalize "services" into reusable methods, rather than being specifically for 1 route (although that's ok too)

Also this is a phenomenal description, definitely setting a great precedent, we all have to step up the game now lol