Proctor LEVEL1_VIVA3

SimpleExaminer portal wala submitted ZIP chahta hai. Local extra changes mat dikhana.

Suggested flow1) Portal ZIP download
2) Extract
3) venv + pip install -r requirements.txt
4) flask run / python app.py

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.

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

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

SimpleCache = pehli baar hisaab karke copy rakh lo, doosri baar copy dikha do.

Baar-baar same expensive kaam (DB query, counting bookings) mat karo. Result Redis jaise store mein timeout ke saath rakh do.

Cache hit: key mil gayi, DB skip. Cache miss: DB se lao, SET karo, return karo.

Tradeoff: speed vs stale data. Admin naya venue add kare aur cache 50s ka ho to user purani list dekh sakta hai — isliye write pe invalidation zaroori hai.

Browser cache, Flask-Caching, Redis alag layers hain. MAD2 examiner Redis + @cache.cached code dekhta hai.

Example

@cache.cached(timeout=50, query_string=True)
@app.route('/api/shows')
def shows():
    return jsonify([s.serialize() for s in Show.query.all()])

Project example: Admin dashboard counts / venues list cache. Create/update/delete ke baad cache.delete('venues').

Viva tipprint('DB queried') function ke andar laga ke miss/hit demo karo — hit pe print nahi chalega.

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'))

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

SimpleCASCADE = parent gaya to bacche bhi. Restrict = pehle bacche sambhalo.

ON DELETE CASCADE SQL. SQLAlchemy cascade='all, delete-orphan' collection se orphans.
Opposite auto nahi — child delete se parent nahi marata.

Venue delete: bookings restrict (safer viva) ya cascade+cancel policy. Examiner design poochta hai.

ON UPDATE CASCADE PK change — rare. SET NULL, RESTRICT bhi options.

Example

shows = db.relationship('Show', cascade='all, delete-orphan', back_populates='venue')

Project example: Show belongs Venue delete-orphan. Booking venue pe restrict — 'reassign first'.

Viva tipVenue delete pe bookings: restrict (mat delete) ya cascade+refund policy. Examiner design poochta hai. Cascade UPDATE bhi hota hai (PK change) — rare.

SimpleHTML structure, CSS styling. Templates mein semantic tags + classes. Responsive ke liye viewport + flex/grid/bootstrap.

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

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

SimpleForeign key dusri table ke PK ko point karti hai — relationship banati hai.

Example

lot_id = db.Column(db.Integer, db.ForeignKey('lot.id'), nullable=False)

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.