Create FastAPI REST API service with SQLite database

- Set up FastAPI application with CORS support
- Implement SQLite database with SQLAlchemy ORM
- Create User model with CRUD operations
- Add Alembic for database migrations
- Include health check and documentation endpoints
- Set up proper project structure with organized modules
- Add comprehensive README with setup instructions
- Configure Ruff for code linting and formatting

README.md

@@ -1,3 +1,88 @@
-# FastAPI Application
+# REST API Service
 
-This is a FastAPI application bootstrapped by BackendIM, the AI-powered backend generation platform.
+A REST API service built with FastAPI and SQLite, providing user management functionality.
+
+## Features
+
+- FastAPI web framework
+- SQLite database with SQLAlchemy ORM
+- Alembic database migrations
+- CRUD operations for users
+- Health check endpoint
+- Auto-generated OpenAPI documentation
+- CORS support
+
+## Project Structure
+
+```
+├── main.py                 # FastAPI application entry point
+├── requirements.txt        # Python dependencies
+├── alembic.ini            # Alembic configuration
+├── alembic/               # Database migrations
+│   ├── env.py
+│   ├── script.py.mako
+│   └── versions/
+│       └── 001_initial_migration.py
+└── app/
+    ├── __init__.py
+    ├── db/
+    │   ├── __init__.py
+    │   ├── base.py        # SQLAlchemy base
+    │   └── session.py     # Database session configuration
+    ├── models/
+    │   ├── __init__.py
+    │   └── user.py        # User model
+    ├── schemas/
+    │   ├── __init__.py
+    │   └── user.py        # Pydantic schemas
+    └── crud/
+        ├── __init__.py
+        └── user.py        # CRUD operations
+```
+
+## Installation
+
+1. Install dependencies:
+```bash
+pip install -r requirements.txt
+```
+
+2. Run database migrations:
+```bash
+alembic upgrade head
+```
+
+3. Start the application:
+```bash
+uvicorn main:app --host 0.0.0.0 --port 8000 --reload
+```
+
+## API Endpoints
+
+- `GET /` - Service information
+- `GET /health` - Health check
+- `GET /docs` - OpenAPI documentation
+- `GET /redoc` - Alternative API documentation
+- `POST /users/` - Create a new user
+- `GET /users/` - List all users
+- `GET /users/{user_id}` - Get user by ID
+- `PUT /users/{user_id}` - Update user
+- `DELETE /users/{user_id}` - Delete user
+
+## Database
+
+The application uses SQLite database stored at `/app/storage/db/db.sqlite`.
+
+## Environment Variables
+
+No environment variables are required for basic operation. The application uses SQLite with default settings.
+
+## Development
+
+To run the application in development mode:
+
+```bash
+uvicorn main:app --reload
+```
+
+The API will be available at `http://localhost:8000` with automatic reload on code changes.

alembic.ini

@@ -0,0 +1,42 @@
+[alembic]
+script_location = alembic
+prepend_sys_path = .
+version_path_separator = os
+sqlalchemy.url = sqlite:////app/storage/db/db.sqlite
+version_locations = %(here)s/alembic/versions
+
+[post_write_hooks]
+
+[loggers]
+keys = root,sqlalchemy,alembic
+
+[handlers]
+keys = console
+
+[formatters]
+keys = generic
+
+[logger_root]
+level = WARN
+handlers = console
+qualname =
+
+[logger_sqlalchemy]
+level = WARN
+handlers =
+qualname = sqlalchemy.engine
+
+[logger_alembic]
+level = INFO
+handlers =
+qualname = alembic
+
+[handler_console]
+class = StreamHandler
+args = (sys.stderr,)
+level = NOTSET
+formatter = generic
+
+[formatter_generic]
+format = %(levelname)-5.5s [%(name)s] %(message)s
+datefmt = %H:%M:%S

alembic/env.py

@@ -0,0 +1,50 @@
+from logging.config import fileConfig
+from sqlalchemy import engine_from_config
+from sqlalchemy import pool
+from alembic import context
+import sys
+import os
+
+sys.path.append(os.path.join(os.path.dirname(__file__), ".."))
+
+from app.db.base import Base
+
+config = context.config
+
+if config.config_file_name is not None:
+    fileConfig(config.config_file_name)
+
+target_metadata = Base.metadata
+
+
+def run_migrations_offline() -> None:
+    url = config.get_main_option("sqlalchemy.url")
+    context.configure(
+        url=url,
+        target_metadata=target_metadata,
+        literal_binds=True,
+        dialect_opts={"paramstyle": "named"},
+    )
+
+    with context.begin_transaction():
+        context.run_migrations()
+
+
+def run_migrations_online() -> None:
+    connectable = engine_from_config(
+        config.get_section(config.config_ini_section),
+        prefix="sqlalchemy.",
+        poolclass=pool.NullPool,
+    )
+
+    with connectable.connect() as connection:
+        context.configure(connection=connection, target_metadata=target_metadata)
+
+        with context.begin_transaction():
+            context.run_migrations()
+
+
+if context.is_offline_mode():
+    run_migrations_offline()
+else:
+    run_migrations_online()

alembic/script.py.mako

@@ -0,0 +1,24 @@
+"""${message}
+
+Revision ID: ${up_revision}
+Revises: ${down_revision | comma,n}
+Create Date: ${create_date}
+
+"""
+from alembic import op
+import sqlalchemy as sa
+${imports if imports else ""}
+
+# revision identifiers, used by Alembic.
+revision = ${repr(up_revision)}
+down_revision = ${repr(down_revision)}
+branch_labels = ${repr(branch_labels)}
+depends_on = ${repr(depends_on)}
+
+
+def upgrade() -> None:
+    ${upgrades if upgrades else "pass"}
+
+
+def downgrade() -> None:
+    ${downgrades if downgrades else "pass"}

alembic/versions/001_initial_migration.py

@@ -0,0 +1,43 @@
+"""Initial migration
+
+Revision ID: 001
+Revises:
+Create Date: 2024-01-01 00:00:00.000000
+
+"""
+
+from alembic import op
+import sqlalchemy as sa
+
+# revision identifiers, used by Alembic.
+revision = "001"
+down_revision = None
+branch_labels = None
+depends_on = None
+
+
+def upgrade() -> None:
+    # Create users table
+    op.create_table(
+        "users",
+        sa.Column("id", sa.Integer(), nullable=False),
+        sa.Column("email", sa.String(), nullable=False),
+        sa.Column("name", sa.String(), nullable=False),
+        sa.Column("is_active", sa.Boolean(), nullable=True),
+        sa.Column(
+            "created_at",
+            sa.DateTime(timezone=True),
+            server_default=sa.text("(CURRENT_TIMESTAMP)"),
+            nullable=True,
+        ),
+        sa.Column("updated_at", sa.DateTime(timezone=True), nullable=True),
+        sa.PrimaryKeyConstraint("id"),
+    )
+    op.create_index(op.f("ix_users_email"), "users", ["email"], unique=True)
+    op.create_index(op.f("ix_users_id"), "users", ["id"], unique=False)
+
+
+def downgrade() -> None:
+    op.drop_index(op.f("ix_users_id"), table_name="users")
+    op.drop_index(op.f("ix_users_email"), table_name="users")
+    op.drop_table("users")

app/__init__.py

@@ -0,0 +1 @@
+# FastAPI REST API Service

app/crud/__init__.py

@@ -0,0 +1 @@
+# CRUD module

app/crud/user.py

@@ -0,0 +1,43 @@
+from sqlalchemy.orm import Session
+from app.models.user import User
+from app.schemas.user import UserCreate
+
+
+def get_user(db: Session, user_id: int):
+    return db.query(User).filter(User.id == user_id).first()
+
+
+def get_user_by_email(db: Session, email: str):
+    return db.query(User).filter(User.email == email).first()
+
+
+def get_users(db: Session, skip: int = 0, limit: int = 100):
+    return db.query(User).offset(skip).limit(limit).all()
+
+
+def create_user(db: Session, user: UserCreate):
+    db_user = User(**user.dict())
+    db.add(db_user)
+    db.commit()
+    db.refresh(db_user)
+    return db_user
+
+
+def update_user(db: Session, user_id: int, user: UserCreate):
+    db_user = db.query(User).filter(User.id == user_id).first()
+    if db_user:
+        update_data = user.dict(exclude_unset=True)
+        for field, value in update_data.items():
+            setattr(db_user, field, value)
+        db.commit()
+        db.refresh(db_user)
+    return db_user
+
+
+def delete_user(db: Session, user_id: int):
+    db_user = db.query(User).filter(User.id == user_id).first()
+    if db_user:
+        db.delete(db_user)
+        db.commit()
+        return True
+    return False

app/db/__init__.py

@@ -0,0 +1 @@
+# Database module

app/db/base.py

@@ -0,0 +1,3 @@
+from sqlalchemy.ext.declarative import declarative_base
+
+Base = declarative_base()

app/db/session.py

@@ -0,0 +1,14 @@
+from sqlalchemy import create_engine
+from sqlalchemy.orm import sessionmaker
+from pathlib import Path
+
+DB_DIR = Path("/app") / "storage" / "db"
+DB_DIR.mkdir(parents=True, exist_ok=True)
+
+SQLALCHEMY_DATABASE_URL = f"sqlite:///{DB_DIR}/db.sqlite"
+
+engine = create_engine(
+    SQLALCHEMY_DATABASE_URL, connect_args={"check_same_thread": False}
+)
+
+SessionLocal = sessionmaker(autocommit=False, autoflush=False, bind=engine)

app/models/__init__.py

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+# Models module

app/models/user.py

@@ -0,0 +1,14 @@
+from sqlalchemy import Column, Integer, String, DateTime, Boolean
+from sqlalchemy.sql import func
+from app.db.base import Base
+
+
+class User(Base):
+    __tablename__ = "users"
+
+    id = Column(Integer, primary_key=True, index=True)
+    email = Column(String, unique=True, index=True, nullable=False)
+    name = Column(String, nullable=False)
+    is_active = Column(Boolean, default=True)
+    created_at = Column(DateTime(timezone=True), server_default=func.now())
+    updated_at = Column(DateTime(timezone=True), onupdate=func.now())

app/schemas/__init__.py

@@ -0,0 +1 @@
+# Schemas module

app/schemas/user.py

@@ -0,0 +1,22 @@
+from pydantic import BaseModel, EmailStr
+from datetime import datetime
+from typing import Optional
+
+
+class UserBase(BaseModel):
+    email: EmailStr
+    name: str
+    is_active: bool = True
+
+
+class UserCreate(UserBase):
+    pass
+
+
+class UserResponse(UserBase):
+    id: int
+    created_at: datetime
+    updated_at: Optional[datetime] = None
+
+    class Config:
+        from_attributes = True

main.py

@@ -0,0 +1,98 @@
+from fastapi import FastAPI, HTTPException, Depends
+from fastapi.middleware.cors import CORSMiddleware
+from sqlalchemy.orm import Session
+
+from app.db.session import SessionLocal, engine
+from app.db.base import Base
+from app.schemas.user import UserCreate, UserResponse
+from app.crud.user import create_user, get_user, get_users, update_user, delete_user
+
+# Create database tables
+Base.metadata.create_all(bind=engine)
+
+app = FastAPI(
+    title="REST API Service",
+    description="A REST API service built with FastAPI and SQLite",
+    version="1.0.0",
+    docs_url="/docs",
+    redoc_url="/redoc",
+    openapi_url="/openapi.json",
+)
+
+# CORS middleware
+app.add_middleware(
+    CORSMiddleware,
+    allow_origins=["*"],
+    allow_credentials=True,
+    allow_methods=["*"],
+    allow_headers=["*"],
+)
+
+
+# Dependency to get database session
+def get_db():
+    db = SessionLocal()
+    try:
+        yield db
+    finally:
+        db.close()
+
+
+@app.get("/")
+async def root():
+    return {
+        "title": "REST API Service",
+        "description": "A REST API service built with FastAPI and SQLite",
+        "documentation": "/docs",
+        "health_check": "/health",
+    }
+
+
+@app.get("/health")
+async def health_check():
+    return {"status": "healthy", "service": "REST API Service"}
+
+
+# User endpoints
+@app.post("/users/", response_model=UserResponse)
+async def create_user_endpoint(user: UserCreate, db: Session = Depends(get_db)):
+    db_user = create_user(db=db, user=user)
+    return db_user
+
+
+@app.get("/users/", response_model=list[UserResponse])
+async def read_users(skip: int = 0, limit: int = 100, db: Session = Depends(get_db)):
+    users = get_users(db, skip=skip, limit=limit)
+    return users
+
+
+@app.get("/users/{user_id}", response_model=UserResponse)
+async def read_user(user_id: int, db: Session = Depends(get_db)):
+    db_user = get_user(db, user_id=user_id)
+    if db_user is None:
+        raise HTTPException(status_code=404, detail="User not found")
+    return db_user
+
+
+@app.put("/users/{user_id}", response_model=UserResponse)
+async def update_user_endpoint(
+    user_id: int, user: UserCreate, db: Session = Depends(get_db)
+):
+    db_user = update_user(db=db, user_id=user_id, user=user)
+    if db_user is None:
+        raise HTTPException(status_code=404, detail="User not found")
+    return db_user
+
+
+@app.delete("/users/{user_id}")
+async def delete_user_endpoint(user_id: int, db: Session = Depends(get_db)):
+    success = delete_user(db=db, user_id=user_id)
+    if not success:
+        raise HTTPException(status_code=404, detail="User not found")
+    return {"message": "User deleted successfully"}
+
+
+if __name__ == "__main__":
+    import uvicorn
+
+    uvicorn.run(app, host="0.0.0.0", port=8000)

requirements.txt

@@ -0,0 +1,6 @@
+fastapi==0.104.1
+uvicorn[standard]==0.24.0
+sqlalchemy==2.0.23
+pydantic[email]==2.5.0
+alembic==1.13.0
+ruff==0.1.7