Database Showdown#

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Need relationships? → PostgreSQL
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Need flexibility?  → MongoDB
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Need real-time?    → Firebase
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Just need simple?  → SQLite

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CREATE TABLE users (
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    id SERIAL PRIMARY KEY,
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    name VARCHAR(100),
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    email VARCHAR(255) UNIQUE
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);
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CREATE TABLE posts (
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    id SERIAL PRIMARY KEY,
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    user_id INTEGER REFERENCES users(id),
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    title VARCHAR(255),
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    content TEXT
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);
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-- Get user with their posts
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SELECT users.name, posts.title
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FROM users
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JOIN posts ON users.id = posts.user_id;

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// User document
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{
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  "_id": ObjectId("..."),
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  "name": "LUKKID",
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  "skills": ["Python", "React", "Node.js"],
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  "projects": [
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    {
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      "name": "Portfolio",
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      "tech": ["Next.js", "TailwindCSS"]
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    }
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  ]
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}
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// Query
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db.users.find({ "skills": "Python" })

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import { initializeApp } from 'firebase/app';
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import { getFirestore, collection, onSnapshot } from 'firebase/firestore';
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const db = getFirestore(app);
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// Real-time listener
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onSnapshot(collection(db, 'messages'), (snapshot) => {
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  snapshot.docChanges().forEach((change) => {
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    if (change.type === 'added') {
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      console.log('New message:', change.doc.data());
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    }
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  });
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});