Viva Prep

SimpleProject overview: problem → roles → main entities → key flows (register, book, admin approve).

Viva tip1 minute elevator pitch ready rakho, phir demo.

Simplestatic/ folder CSS, JS, images. url_for('static', filename=...) se link.

Example

<link rel="stylesheet" href="{{ url_for('static', filename='css/app.css') }}">

SimpleCelery = background naukri. HTTP request ko 10 second email bhejne ke liye mat rokna.

Distributed task queue: aap function ko abhi nahi, worker process mein later/retry/schedule pe chalaate ho.

MAD2 typical jobs: daily reminder mail, monthly HTML report, user-triggered CSV export.

Web request 200ms hona chahiye. 10,000 emails request thread mein = timeout. Worker alag CPU pe kaam kare.

Redis broker chahiye. Beat alag process schedule ke liye.

Example

@celery.task
def daily_reminder():
    for u in User.query.filter_by(active=True):
        send_mail(u.email, 'Book something today!')

Project example: User Export click → 202 Accepted. Worker CSV + email. Daily 6pm Beat reminder.

Viva tipWorker + Redis bina Beat ke user-triggered chalega. Scheduled jobs ke liye Beat bhi chahiye.

SimpleExported CSV download folder/MailHog se open — columns verify. Celery job ke baad file path dikhao.

SimpleDemo script pehle se practice: 5–7 min, Admin + User roles, saare mandatory features.

Suggested flow1) Register/login user
2) Admin login — CRUD
3) Approval/blacklist
4) Booking/apply + edge case
5) Search
6) Logout

Viva tipBolte-bolte dikhao. Code tab kholna jab poochhein.

SimpleValidation = input rules: required, email format, length, unique. Frontend UX, backend security — dono.

Example

if not email or '@' not in email:
    flash('Invalid email')
    return redirect(request.url)
if User.query.filter_by(email=email).first():
    flash('Email taken')

SimpleExported CSV download folder/MailHog se open — columns verify. Celery job ke baad file path dikhao.

SimpleLive UI change: relevant CSS/HTML template kholo — color, margin, flex, bootstrap class. Save + hard refresh.

Example

/* button red */
.btn-primary { background: red; }

/* center navbar item */
.navbar { justify-content: center; }

Viva tipDevTools se pehle try, phir file mein permanent change.

SimpleDemo script pehle se practice: 5–7 min, Admin + User roles, saare mandatory features.

Suggested flow1) Register/login user
2) Admin login — CRUD
3) Approval/blacklist
4) Booking/apply + edge case
5) Search
6) Logout

Viva tipBolte-bolte dikhao. Code tab kholna jab poochhein.

SimpleJOIN related tables ek result mein. Inner = match only; left = left side sab + match.

Example

db.session.query(Booking, User).join(User).filter(User.id == uid).all()

SimpleMAD1 typical: Browser → Flask routes → validate/auth → SQLAlchemy → SQLite → Jinja response.

Suggested flowRequest → Route → Auth check → DB → render_template / redirect

SimpleCode explain formula: input kya aaya → auth/validation → DB change → response/UI.

Viva tipFunction signature + 3-4 important lines + edge case.

Simplemodels.py = har table ki class: columns, PK/FK, relationships. Yeh Model layer hai.

Suggested flow1) Classes list karo
2) Har table ka kaam 1 line
3) Relationships (1-M / M-M)
4) Constraints (unique, nullable)

Example

class Lot(db.Model):
    id = db.Column(db.Integer, primary_key=True)
    name = db.Column(db.String(80), nullable=False)
    spots = db.relationship('Spot', backref='lot', lazy=True)

Simpledb.relationship se object graph: lot.spots, booking.user. backref reverse side auto deta hai.

Example

spots = db.relationship('Spot', backref='lot', cascade='all, delete-orphan')

Simplemodels.py = har table ki class: columns, PK/FK, relationships. Yeh Model layer hai.

Suggested flow1) Classes list karo
2) Har table ka kaam 1 line
3) Relationships (1-M / M-M)
4) Constraints (unique, nullable)

Example

class Lot(db.Model):
    id = db.Column(db.Integer, primary_key=True)
    name = db.Column(db.String(80), nullable=False)
    spots = db.relationship('Spot', backref='lot', lazy=True)

Simplebackref reverse attribute auto banata hai. back_populates dono sides explicitly naam dete ho — clearer.

Example

# backref
spots = db.relationship('Spot', backref='lot')
# spot.lot available

# back_populates
spots = db.relationship('Spot', back_populates='lot')
# Spot.lot = db.relationship('Lot', back_populates='spots')

SimpleORM = Object Relational Mapping. Tables → Python classes. Raw SQL kam likhte ho.

Example

class User(db.Model):
    id = db.Column(db.Integer, primary_key=True)
    email = db.Column(db.String(120), unique=True)

User.query.get(5)  # SELECT ... WHERE id=5

SimpleSQLite file-based DB — setup easy, MAD1 ke liye perfect. Production heavy traffic pe Postgres better.

Example

SQLALCHEMY_DATABASE_URI = 'sqlite:///app.db'

SimpleRelational tables SQL ACID FK. NoSQL flexible schema, scale writes. MAD2 SQL + Redis side-cache.

Pick: bookings integrity → SQL. Session cache → Redis.

Pehle 1-line definition, phir related MAD2 layer (Vue SFC / Flask route / models.py / tasks.py / Redis).

4-line formula: input kahan se aaya, auth/validation kaunsa, DB ya cache ya Celery, kya return.

Related mix mat karo — cache ≠ Celery, authentication ≠ authorization, v-if ≠ v-show, Beat ≠ Worker. Follow-up ke liye ek difference ready rakho.

Project example: models relational. cache Redis.

SimplePehle 1-line definition, phir apne MAD1 project mein file dikhao, phir chhota example.

Suggested flow1) Concept kya hai?
2) Mere code mein kahan?
3) Example / demo
4) Edge case

Example

# related file: models.py / routes / template
# formula: request → check/auth → DB → render/redirect

Viva tipExact line yaad nahi to honestly related part dikhao. Bluff mat karo.

SimpleJWT teen tukde ki signed chitthi: header.payload.signature. Padhi ja sakti hai, badli nahi ja sakti.

Encoded (Base64) + signed, encrypted nahi (JWE alag). Payload mein password mat daalo — koi jwt.io pe dekh lega.

Login pe server secret se HMAC (HS256). Har API Authorization: Bearer <token>.
Expiry exp. Change payload → signature fail → 401.

Session MAD1 server yaad rakhta. JWT MAD2 client rakhta, server stateless-ish.

Example

eyJhbGciOiJIUzI1NiJ9.{"sub":1,"role":"admin"}.signature
# Authorization: Bearer <token>

Project example: POST /login → token LS. fetch interceptor header. @jwt_required APIs.

Viva tipAlgo HS256. Secret env var. jwt.io pe payload dikhao, secret public site pe mat paste.

SimpleDemo script pehle se practice: 5–7 min, Admin + User roles, saare mandatory features.

Suggested flow1) Register/login user
2) Admin login — CRUD
3) Approval/blacklist
4) Booking/apply + edge case
5) Search
6) Logout

Viva tipBolte-bolte dikhao. Code tab kholna jab poochhein.

SimpleJWT teen tukde ki signed chitthi: header.payload.signature. Padhi ja sakti hai, badli nahi ja sakti.

Encoded (Base64) + signed, encrypted nahi (JWE alag). Payload mein password mat daalo — koi jwt.io pe dekh lega.

Login pe server secret se HMAC (HS256). Har API Authorization: Bearer <token>.
Expiry exp. Change payload → signature fail → 401.

Session MAD1 server yaad rakhta. JWT MAD2 client rakhta, server stateless-ish.

Example

eyJhbGciOiJIUzI1NiJ9.{"sub":1,"role":"admin"}.signature
# Authorization: Bearer <token>

Project example: POST /login → token LS. fetch interceptor header. @jwt_required APIs.

Viva tipAlgo HS256. Secret env var. jwt.io pe payload dikhao, secret public site pe mat paste.

SimpleNayi booking flow: UI form/button → route POST → login_required → validate seats → insert Booking → commit → redirect/flash.

Suggested flowBrowser → Flask route → Auth → Business rules → SQLAlchemy → SQLite → Response template/JSON

SimpleNayi booking flow: UI form/button → route POST → login_required → validate seats → insert Booking → commit → redirect/flash.

Suggested flowBrowser → Flask route → Auth → Business rules → SQLAlchemy → SQLite → Response template/JSON

SimpleMAD1 frontend usually Jinja templates + HTML/CSS/Bootstrap (+ thoda JS). MAD2 pe Vue ho to clearly bolo.

SimpleMAD1 frontend usually Jinja templates + HTML/CSS/Bootstrap (+ thoda JS). MAD2 pe Vue ho to clearly bolo.

SimpleParent-child: parent template mein child component. Props parent→child, emit child→parent.

SimpleParent-child: parent template mein child component. Props parent→child, emit child→parent.

SimpleViva wrap-up hai. Short thanks + confirm submission ZIP latest hai.

SimpleLive UI change: relevant CSS/HTML template kholo — color, margin, flex, bootstrap class. Save + hard refresh.

Example

/* button red */
.btn-primary { background: red; }

/* center navbar item */
.navbar { justify-content: center; }

Viva tipDevTools se pehle try, phir file mein permanent change.

SimplePehle 1-line definition, phir apne MAD1 project mein file dikhao, phir chhota example.

Suggested flow1) Concept kya hai?
2) Mere code mein kahan?
3) Example / demo
4) Edge case

Example

# related file: models.py / routes / template
# formula: request → check/auth → DB → render/redirect

Viva tipExact line yaad nahi to honestly related part dikhao. Bluff mat karo.

Simplemodels.py = har table ki class: columns, PK/FK, relationships. Yeh Model layer hai.

Suggested flow1) Classes list karo
2) Har table ka kaam 1 line
3) Relationships (1-M / M-M)
4) Constraints (unique, nullable)

Example

class Lot(db.Model):
    id = db.Column(db.Integer, primary_key=True)
    name = db.Column(db.String(80), nullable=False)
    spots = db.relationship('Spot', backref='lot', lazy=True)

SimpleLive UI change: relevant CSS/HTML template kholo — color, margin, flex, bootstrap class. Save + hard refresh.

Example

/* button red */
.btn-primary { background: red; }

/* center navbar item */
.navbar { justify-content: center; }

Viva tipDevTools se pehle try, phir file mein permanent change.

SimpleViva wrap-up hai. Short thanks + confirm submission ZIP latest hai.

SimpleRedis box hai, Celery us box se kaam uthane wala worker hai — same cheez nahi.

Redis: store (cache keys) + queue (broker lists).
Celery: Python library jo tasks define karti hai, .delay() se queue mein daalti hai, worker execute karta hai.

Dono localhost pe ho sakte hain. Alag Redis DB index use karo. Redis band = cache miss + Celery stuck.

Example

Celery: broker_url='redis://localhost:6379/0'
Cache:  CACHE_REDIS_URL='redis://localhost:6379/1'

Project example: export_csv.delay(user_id) Flask se. Worker Redis se task uthata hai, CSV+email. Cache alag keys venues.

Viva tipAgar possible ho to cache db=1, broker db=0 — keys mix nahi hoti.

SimpleMailHog local fake post office — email internet pe nahi jaata, browser mein dikhta hai.

SMTP 1025, Web UI 8025. Viva demo gold. Credentials nahi.

Real Gmail SMTP student accounts pe block common — MailHog safer.

Flask-Mail / SMTP se mail. Local MailHog fake server: SMTP 1025, UI 8025 — internet nahi, viva safe.

Asli send Celery task mein, request thread mein nahi. Beat 6pm reminder, export ke baad CSV attach optional.

MAIL_SERVER localhost demo. Gmail SMTP student account pe block common. Body mein user name personalization examiner dekhta hai.

Example

MAIL_SERVER=localhost
MAIL_PORT=1025
# http://localhost:8025

Project example: Reminder task → MailHog list → HTML body user name ke saath.

SimpleBeat clock hai, Worker haath hai. Clock kaam nahi karti, haath nahi sochte kab.

Worker: @celery.task execute. Beat: crontab padhke due time pe queue mein daal.
Sirf worker = scheduled nahi. Sirf beat = queue bhar jaaye, koi run nahi.

Dono ke saath redis-server. Logs mein 'Sending due task' Beat, 'Task succeeded' Worker.

Example

celery -A app.celery worker -l info
celery -A app.celery beat -l info

Project example: daily_reminder Beat 18:00. Worker MailHog. Export worker-only (button).

Viva tipSirf worker = scheduled jobs nahi chalenge. Sirf beat = queue bhar jaaye, koi run nahi karega.

SimpleMailHog local fake post office — email internet pe nahi jaata, browser mein dikhta hai.

SMTP 1025, Web UI 8025. Viva demo gold. Credentials nahi.

Real Gmail SMTP student accounts pe block common — MailHog safer.

Flask-Mail / SMTP se mail. Local MailHog fake server: SMTP 1025, UI 8025 — internet nahi, viva safe.

Asli send Celery task mein, request thread mein nahi. Beat 6pm reminder, export ke baad CSV attach optional.

MAIL_SERVER localhost demo. Gmail SMTP student account pe block common. Body mein user name personalization examiner dekhta hai.

Example

MAIL_SERVER=localhost
MAIL_PORT=1025
# http://localhost:8025

Project example: Reminder task → MailHog list → HTML body user name ke saath.

SimpleSMTP = Simple Mail Transfer Protocol — email bhejne ka standard. Flask-Mail / smtplib se reminders/reports.

Example

from flask_mail import Message
msg = Message('Subject', recipients=[user.email])
msg.body = 'Hello'
mail.send(msg)

Viva tipViva mein MailHog/inbox dikhao. Port 587 TLS common; local pe MailHog 1025.

SimpleLive Flask coding: chhota route likho, save, browser/curl se test. Syntax error terminal mein padho.

Example

@app.route('/ping')
def ping():
    return jsonify(ok=True)

@app.route('/even/<int:n>')
def even(n):
    return 'even' if n % 2 == 0 else 'odd'

SimpleRBAC = Role Based Access Control. Roles (admin/user) se permissions milti hain, har user pe alag list nahi.

Example

if current_user.role != 'admin':
    flash('Not allowed')
    return redirect(url_for('user.home'))

SimpleSync line pe ruk jao (2+2). Async I/O pe wait karte hue baaki kaam chalte (fetch, Celery).

JS async ≠ Celery async jobs. Context se bolo.

Why async jobs: slow/scheduled/bulk off request thread.

Pehle 1-line definition, phir related MAD2 layer (Vue SFC / Flask route / models.py / tasks.py / Redis).

4-line formula: input kahan se aaya, auth/validation kaunsa, DB ya cache ya Celery, kya return.

Related mix mat karo — cache ≠ Celery, authentication ≠ authorization, v-if ≠ v-show, Beat ≠ Worker. Follow-up ke liye ek difference ready rakho.

Project example: Login sync hash check fast. Email Celery async. Vue fetch async.

SimpleCode explain formula: input kya aaya → auth/validation → DB change → response/UI.

Viva tipFunction signature + 3-4 important lines + edge case.

SimpleLifecycle = component ki zindagi ke stages. API call tab jab DOM ready ho — mounted.

created: instance bani, this data, DOM nahi. mounted/onMounted: page pe aa gaya — fetch, Chart.js, setInterval.
updated: data change ke baad. unmounted: cleanup (clearInterval) warna memory leak.

Dashboards onMounted isliye: canvas/API tab valid. created mein $el nahi.

Composition: onMounted(() => {}) setup ke andar.

Example

export default {
  async mounted() {
    const r = await fetch('/api/venues')
    this.venues = await r.json()
  }
}

Project example: Venues.vue mounted fetch list. Clock component unmounted pe interval clear.

Viva tipcreated: data setup, DOM nahi. mounted/onMounted: $el mil gaya — fetch yahi. Dashboards isliye onMounted use karti hain.

SimpleDemo script pehle se practice: 5–7 min, Admin + User roles, saare mandatory features.

Suggested flow1) Register/login user
2) Admin login — CRUD
3) Approval/blacklist
4) Booking/apply + edge case
5) Search
6) Logout

Viva tipBolte-bolte dikhao. Code tab kholna jab poochhein.

Simpledb.relationship se object graph: lot.spots, booking.user. backref reverse side auto deta hai.

Example

spots = db.relationship('Spot', backref='lot', cascade='all, delete-orphan')

SimpleStack bolo: Python, Flask, Jinja2, SQLAlchemy, SQLite, HTML/CSS/Bootstrap, maybe Chart.js.

SimpleDemo script pehle se practice: 5–7 min, Admin + User roles, saare mandatory features.

Suggested flow1) Register/login user
2) Admin login — CRUD
3) Approval/blacklist
4) Booking/apply + edge case
5) Search
6) Logout

Viva tipBolte-bolte dikhao. Code tab kholna jab poochhein.

SimpleViva wrap-up hai. Short thanks + confirm submission ZIP latest hai.

Simplemodels.py = har table ki class: columns, PK/FK, relationships. Yeh Model layer hai.

Suggested flow1) Classes list karo
2) Har table ka kaam 1 line
3) Relationships (1-M / M-M)
4) Constraints (unique, nullable)

Example

class Lot(db.Model):
    id = db.Column(db.Integer, primary_key=True)
    name = db.Column(db.String(80), nullable=False)
    spots = db.relationship('Spot', backref='lot', lazy=True)

SimpleGitHub repo public/private policy ke hisaab, MAD-1 collaborator add, commits dikhao.

Repo → Settings → Collaborators → instructor added.
Commits: git log / GitHub History — regular commits better, ek dum 1 commit suspicious.
README + report mein AI usage likha hona chahiye agar use kiya.

Simplemodels.py = har table ki class: columns, PK/FK, relationships. Yeh Model layer hai.

Suggested flow1) Classes list karo
2) Har table ka kaam 1 line
3) Relationships (1-M / M-M)
4) Constraints (unique, nullable)

Example

class Lot(db.Model):
    id = db.Column(db.Integer, primary_key=True)
    name = db.Column(db.String(80), nullable=False)
    spots = db.relationship('Spot', backref='lot', lazy=True)

SimpleVue = UI ka smart assistant. Data badlo, screen khud update. MAD1 Jinja har click pe naya HTML.

Progressive frontend framework. Components, reactivity, directives.

MAD2 SPA: ek index.html, Vue Router pages, Flask sirf JSON.

Fayde: easy, SFC, docs. Vs React: templates HTML-like, course sikhata hai. Vs plain JS: baar-baar DOM mat chhedo.

Example

<!-- HelloWorld.vue -->
<template>
  <h1>{{ msg }}</h1>
</template>
<script>
export default { data() { return { msg: 'Hello' } } }
</script>

Project example: Navbar.vue + views (Login, Dashboard). data() / setup() reactive. fetch APIs.

Viva tipFayde: easy, SFC, reactivity. Vs React: chhota learning curve. Vs plain JS: UI state auto-update.

SimpleCode dikhao to pehle related file: models → route → template. Flow explain karte hue lines padho.

SimpleMAD1 frontend usually Jinja templates + HTML/CSS/Bootstrap (+ thoda JS). MAD2 pe Vue ho to clearly bolo.

SimpleSearch: form/query param → ilike filter → results template.

Example

q = request.args.get('q', '').strip()
lots = Lot.query.filter(Lot.name.ilike(f'%{q}%')).all()

SimpleMAD1 frontend usually Jinja templates + HTML/CSS/Bootstrap (+ thoda JS). MAD2 pe Vue ho to clearly bolo.

SimpleSearch: form/query param → ilike filter → results template.

Example

q = request.args.get('q', '').strip()
lots = Lot.query.filter(Lot.name.ilike(f'%{q}%')).all()

SimpleDemo script pehle se practice: 5–7 min, Admin + User roles, saare mandatory features.

Suggested flow1) Register/login user
2) Admin login — CRUD
3) Approval/blacklist
4) Booking/apply + edge case
5) Search
6) Logout

Viva tipBolte-bolte dikhao. Code tab kholna jab poochhein.

SimpleTheory = concepts: ORM, MVC, auth vs authz, Jinja inheritance, sessions. 1-line def + project example.

SimpleLive Flask coding: chhota route likho, save, browser/curl se test. Syntax error terminal mein padho.

Example

@app.route('/ping')
def ping():
    return jsonify(ok=True)

@app.route('/even/<int:n>')
def even(n):
    return 'even' if n % 2 == 0 else 'odd'

SimpleViva wrap-up hai. Short thanks + confirm submission ZIP latest hai.

SimpleTheory = concepts: ORM, MVC, auth vs authz, Jinja inheritance, sessions. 1-line def + project example.

SimpleIndex = column pe shortcut book — WHERE/JOIN tez. PK auto-indexed. Email/unique filters pe index socho.

Example

email = db.Column(db.String(120), unique=True, index=True)

SimpleNormalisation: redundant data kam, tables todna. 1NF atomic, 2NF partial dep hatao, 3NF transitive dep hatao.

Viva tip

Exampleuser address alag table vs har booking mein dubara store.

SimpleNormalisation: redundant data kam, tables todna. 1NF atomic, 2NF partial dep hatao, 3NF transitive dep hatao.

Viva tip

Exampleuser address alag table vs har booking mein dubara store.

SimpleDijkstra shortest path in weighted graph (non-negative). Priority queue + distances. Parking app se related nahi usually — algo side Q.

SimpleTime complexity input size ke saath time kaise badhta hai.

O(1): dict lookup. O(n): list mein loop. O(n^2): nested loops.

Example

User.query.all() phir Python mein filter = O(n). DB pe indexed WHERE tez.

Search suggestions: prefix index / ILIKE, nai to har keypress pe poori table mat ghumao.

Simple:class object/array/string dynamic CSS.

Purpose dynamic class. Error red.

Directives Vue ke special attributes hain — HTML ko superpower: v-if/v-show, v-for, v-bind (:), v-on (@), v-model.

v-if DOM se hataata/jodta. v-show sirf CSS display. Rare/permission: v-if. Bar-bar toggle: v-show. v-model two-way form. v-bind one-way JS→attribute.

:key v-for pe zaroori warna Vue galat reuse. v-html XSS. Secret UI ke liye sirf v-if kaafi nahi — API 403 bhi.

MAD1 Jinja server HTML. MAD2 yeh directives browser mein reactive.

Example

<div :class="{ 'text-danger': error, 'fw-bold': important }">Msg</div>

Project example: :class="{ 'text-danger': error }"

SimpleFlask lightweight Python web framework — routes, request/response, templates. MAD1 ka backend yahi hai.

Example

from flask import Flask
app = Flask(__name__)

@app.route('/')
def home():
    return 'Hello'

Viva tipFlask micro hai: jo chahiye (DB, login, forms) khud jodte ho.

SimpleFlask lightweight Python web framework — routes, request/response, templates. MAD1 ka backend yahi hai.

Example

from flask import Flask
app = Flask(__name__)

@app.route('/')
def home():
    return 'Hello'

Viva tipFlask micro hai: jo chahiye (DB, login, forms) khud jodte ho.

SimpleCSRF: attacker tumhari logged-in browser se unwanted POST. CSRF token form mein proof hai request genuine hai.

Viva tipFlask-WTF CSRF protect karta hai. Token bina POST reject.

SimpleDemo script pehle se practice: 5–7 min, Admin + User roles, saare mandatory features.

Suggested flow1) Register/login user
2) Admin login — CRUD
3) Approval/blacklist
4) Booking/apply + edge case
5) Search
6) Logout

Viva tipBolte-bolte dikhao. Code tab kholna jab poochhein.

SimplePayload = dabba ke andar samaan (body). JWT payload beech wala claims (encrypted nahi).

POST haan JSON. GET query string. JWT payload vs HTTP payload alag context.

HTTP verbs + status REST ki zabaan. GET read, POST create, PUT replace, PATCH partial, DELETE remove. GET typically no body.

Status: 200 OK, 201 created, 202 accepted (Celery task), 400 bad input, 401 no/bad token, 403 role nahi, 404 missing, 409 conflict (double book), 500 server.

AJAX/fetch page reload nahi. SPA poori isi pe. Postman se bina Vue ke API prove karo — examiner pasand.

Project example: request.get_json() create venue. Token payload user id jwt.io.

SimpleViva wrap-up hai. Short thanks + confirm submission ZIP latest hai.

SimpleLive Flask coding: chhota route likho, save, browser/curl se test. Syntax error terminal mein padho.

Example

@app.route('/ping')
def ping():
    return jsonify(ok=True)

@app.route('/even/<int:n>')
def even(n):
    return 'even' if n % 2 == 0 else 'odd'

SimpleSQLAlchemy Python ka sabse popular ORM hai. MAD1 mein Flask-SQLAlchemy wrapper use hota hai.

db = SQLAlchemy(app)

class Book(db.Model):
    id = db.Column(db.Integer, primary_key=True)
    title = db.Column(db.String(80), nullable=False)

Operations: db.session.add(obj), .commit(), .delete(obj), Model.query.all(), .filter_by(), .get_or_404(id).
db.Model ek class hai (function nahi). db object engine + session + metadata hold karta hai.

SQLALCHEMY_TRACK_MODIFICATIONS=False extra signals band karta hai, performance warning hatati hai.

SimpleORM = Object Relational Mapping. Database tables ko Python classes/objects se map karta hai, raw SQL kam likhni padti hai.

Bina ORM: cursor.execute('SELECT * FROM user WHERE id=?', [5])
ORM se: User.query.get(5) ya db.session.get(User, 5)

Example model

class User(db.Model):
    id = db.Column(db.Integer, primary_key=True)
    email = db.Column(db.String(120), unique=True)

FaydePython mein soch sakte ho, SQL injection se protection (parameterized), relationships easy, DB switch thoda aasan.

Nuksaancomplex queries slow/abstract, seekhne ki layer extra, kabhi raw SQL phir bhi chahiye.

MAD1: SQLAlchemy (Flask-SQLAlchemy). Tables db.create_all() ya migrations se banti hain.

SimpleORM = Object Relational Mapping. Tables → Python classes. Raw SQL kam likhte ho.

Example

class User(db.Model):
    id = db.Column(db.Integer, primary_key=True)
    email = db.Column(db.String(120), unique=True)

User.query.get(5)  # SELECT ... WHERE id=5

Simplecommit changes save. rollback fail pe undo. Transaction consistency ke liye.

Example

try:
    db.session.add(obj)
    db.session.commit()
except Exception:
    db.session.rollback()
    raise

SimpleCode explain formula: input kya aaya → auth/validation → DB change → response/UI.

Viva tipFunction signature + 3-4 important lines + edge case.

Simpleasync function promise return karti hai. await us promise ka result wait karta hai — callback hell kam.

Example

async function loadLots() {
  const res = await fetch('/api/lots');
  const data = await res.json();
  return data;
}

SimpleViva wrap-up hai. Short thanks + confirm submission ZIP latest hai.

SimplePehle 1-line definition, phir apne MAD1 project mein file dikhao, phir chhota example.

Suggested flow1) Concept kya hai?
2) Mere code mein kahan?
3) Example / demo
4) Edge case

Example

# related file: models.py / routes / template
# formula: request → check/auth → DB → render/redirect

Viva tipExact line yaad nahi to honestly related part dikhao. Bluff mat karo.