This content originally appeared on DEV Community and was authored by yashi srivastava
Storing Images in a Database
We don’t store the actual image in the database; instead, we store its link while the image is hosted elsewhere.
Understanding Collections, Schemas & Databases
Collection → Similar to a table in SQL.
Schema → Defines the fields stored in a collection (e.g., id, name, email).
Database (DB) → A container for all collections.
HTTP Methods & Postman
POST → Sends data to the database (used for creating records).
GET → Fetches data from the database.
Postman → A tool to send requests to the backend and check responses.
Backend Function Calls
When we send a POST/GET request from Postman, it's like calling a function.
These functions must be defined in our backend (JS file).
The JS file acts as a medium that queries the database to store or retrieve data.
Postman is like a frontend where we send and request data.
Destructuring & Spread Operator in JavaScript
Destructuring
const obj = { name: "John Doe", email: "john@example.com" };
const { name, email } = obj;
console.log(name); // John Doe
console.log(email); // john@example.com
Makes it easier to access object properties directly.
Spread Operator (...)
const arr1 = [1, 2, 3, 4];
const arr2 = [5, 6];
const arr3 = [...arr1, ...arr2];
console.log(arr3); // [1, 2, 3, 4, 5, 6]
Combines multiple arrays/objects into one.
User Registration & Validations
Validations ensure that only correct data enters the database (e.g., email format, age limit).
When updating an entry, we need to explicitly enable validation:
runValidators: true
Timestamps (createdAt, updatedAt)
Track when a user registered and when they last updated their profile.
Platforms like Instagram use this to filter users based on registration date (e.g., last 7 days, 1 month).
Immutable Fields
Some fields cannot be changed after creation (e.g., emailID).
Must be enforced at the schema level.
API-Level Validation
API acts as a middleware between Postman (client) and the database (server).
API validation checks user data before sending it to the database to:
Avoid unnecessary DB calls (reducing cost & improving performance).
Enhance user experience by preventing delays.
This content originally appeared on DEV Community and was authored by yashi srivastava
yashi srivastava | Sciencx (2025-04-02T22:11:30+00:00) Today’s Learning Update: Backend Basics. Retrieved from https://www.scien.cx/2025/04/02/todays-learning-update-backend-basics/
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