pip install fastapi uvicorn sqlalchemy pydantic[email]

fastapi_project/
├── app/
│   ├── main.py             
│   ├── db/
│   │   └── session.py      
│   └── apps/
│       └── students/       
│           ├── models.py   
│           ├── schemas.py  
│           └── routes.py   
└── requirements.txt

from sqlalchemy import create_engine
from sqlalchemy.ext.declarative import declarative_base
from sqlalchemy.orm import sessionmaker

# ১. ডাটাবেস ফাইলের লোকেশন
SQLALCHEMY_DATABASE_URL = "sqlite:///./sql_app.db"

# ২. ইঞ্জিন তৈরি
engine = create_engine(
    SQLALCHEMY_DATABASE_URL, 
    connect_args={"check_same_thread": False}
)

# ৩. সেশন ফ্যাক্টরি
SessionLocal = sessionmaker(
    autocommit=False, 
    autoflush=False, 
    bind=engine
)

# ৪. বেস ক্লাস
Base = declarative_base()

# ৫. ডিপেন্ডেন্সি (Dependency)
def get_db():
    db = SessionLocal()
    try:
        yield db
    finally:
        db.close()

from sqlalchemy import Column, Integer, String
from app.db.session import Base

class Student(Base):
    __tablename__ = "students"

    id = Column(Integer, primary_key=True, index=True)
    name = Column(String, index=True)
    email = Column(String, unique=True, index=True)
    age = Column(Integer)

from pydantic import BaseModel, EmailStr
from typing import Optional

# কমন ডাটা
class StudentBase(BaseModel):
    name: str
    email: EmailStr
    age: int

# ইনপুট নেওয়ার জন্য (Create)
class StudentCreate(StudentBase):
    pass

# আপডেট করার জন্য (সব ফিল্ড অপশনাল)
class StudentUpdate(BaseModel):
    name: Optional[str] = None
    email: Optional[EmailStr] = None
    age: Optional[int] = None

# ডাটা দেখানোর জন্য (Response)
class StudentResponse(StudentBase):
    id: int

    class Config:
        from_attributes = True

from fastapi import APIRouter, Depends, HTTPException
from sqlalchemy.orm import Session
from typing import List
from app.db.session import get_db
from . import models, schemas

router = APIRouter(prefix="/students", tags=["Students"])

# ১. Create (তৈরি করা)
@router.post("/", response_model=schemas.StudentResponse)
def create_student(student: schemas.StudentCreate, db: Session = Depends(get_db)):
    db_student = models.Student(**student.dict())
    db.add(db_student)
    db.commit()
    db.refresh(db_student)
    return db_student

# ২. Read All (সব দেখা)
@router.get("/", response_model=List[schemas.StudentResponse])
def get_all_students(db: Session = Depends(get_db)):
    return db.query(models.Student).all()

# ৩. Update (পরিবর্তন করা)
@router.put("/{student_id}", response_model=schemas.StudentResponse)
def update_student(student_id: int, student_data: schemas.StudentUpdate, db: Session = Depends(get_db)):
    db_student = db.query(models.Student).filter(models.Student.id == student_id).first()
    
    if not db_student:
        raise HTTPException(status_code=404, detail="Student not found")
    
    # ইউজার শুধু যে ফিল্ডগুলো পাঠিয়েছে সেগুলো বের করা
    updated_info = student_data.dict(exclude_unset=True)
    
    for key, value in updated_info.items():
        setattr(db_student, key, value)
    
    db.commit()
    db.refresh(db_student)
    return db_student

# ৪. Delete (মুছে ফেলা)
@router.delete("/{student_id}")
def delete_student(student_id: int, db: Session = Depends(get_db)):
    db_student = db.query(models.Student).filter(models.Student.id == student_id).first()
    if not db_student:
        raise HTTPException(status_code=404, detail="Student not found")
    
    db.delete(db_student)
    db.commit()
    return {"message": "Successfully Deleted"}

from fastapi import FastAPI
from app.db.session import engine, Base
from app.apps.students import routes as student_routes

# ডাটাবেস টেবিল তৈরি
Base.metadata.create_all(bind=engine)

app = FastAPI(title="Pro Student CRUD")

# রাউট রেজিস্টার করা
app.include_router(student_routes.router)

@app.get("/")
def home():
    return {"message": "Welcome to Student API"}

uvicorn app.main:app --reload