Create REST API with FastAPI and SQLite

- Set up project structure with FastAPI app
- Implement SQLAlchemy models and async database connection
- Create CRUD endpoints for items resource
- Add health endpoint for monitoring
- Configure Alembic for database migrations
- Create comprehensive documentation

generated with BackendIM... (backend.im)

README.md

@@ -1,3 +1,63 @@
-# FastAPI Application
+# Generic REST API Service
 
-This is a FastAPI application bootstrapped by BackendIM, the AI-powered backend generation platform.
+A RESTful API service built with FastAPI and SQLite for database storage.
+
+## Features
+
+- RESTful API endpoints for CRUD operations on items
+- Async SQLAlchemy with SQLite database
+- Database migrations with Alembic
+- Health check endpoint
+- Pydantic schemas for validation
+- Comprehensive API documentation
+
+## Project Structure
+
+```
+├── alembic/             # Database migration files
+├── app/                 # Application package
+│   ├── api/             # API endpoints and routes
+│   ├── db/              # Database connection and utilities
+│   ├── models/          # SQLAlchemy ORM models
+│   └── schemas/         # Pydantic schemas for validation and serialization
+├── main.py              # Application entry point
+├── requirements.txt     # Project dependencies
+└── README.md            # This file
+```
+
+## API Endpoints
+
+- `GET /health`: Check API health status
+- `GET /api/items`: List all items
+- `GET /api/items/{item_id}`: Get a specific item
+- `POST /api/items`: Create a new item
+- `PUT /api/items/{item_id}`: Update an existing item
+- `DELETE /api/items/{item_id}`: Delete an item
+
+## Getting Started
+
+1. Install dependencies:
+   ```
+   pip install -r requirements.txt
+   ```
+
+2. Run the application:
+   ```
+   uvicorn main:app --reload
+   ```
+
+3. Access the API documentation:
+   - Swagger UI: http://localhost:8000/docs
+   - ReDoc: http://localhost:8000/redoc
+
+## Database Migrations
+
+Database migrations are managed with Alembic:
+
+```
+# Apply migrations
+alembic upgrade head
+
+# Create a new migration
+alembic revision --autogenerate -m "description"
+```

alembic.ini

@@ -0,0 +1,89 @@
+# A generic, single database configuration.
+
+[alembic]
+# path to migration scripts
+script_location = alembic
+
+# template used to generate migration files
+# file_template = %%(rev)s_%%(slug)s
+
+# sys.path path, will be prepended to sys.path if present.
+# defaults to the current working directory.
+prepend_sys_path = .
+
+# timezone to use when rendering the date
+# within the migration file as well as the filename.
+# string value is passed to dateutil.tz.gettz()
+# leave blank for localtime
+# timezone =
+
+# max length of characters to apply to the
+# "slug" field
+# truncate_slug_length = 40
+
+# set to 'true' to run the environment during
+# the 'revision' command, regardless of autogenerate
+# revision_environment = false
+
+# set to 'true' to allow .pyc and .pyo files without
+# a source .py file to be detected as revisions in the
+# versions/ directory
+# sourceless = false
+
+# version location specification; this defaults
+# to alembic/versions.  When using multiple version
+# directories, initial revisions must be specified with --version-path
+# version_locations = %(here)s/bar %(here)s/bat alembic/versions
+
+# the output encoding used when revision files
+# are written from script.py.mako
+# output_encoding = utf-8
+
+sqlalchemy.url = sqlite:////app/storage/db/db.sqlite
+
+
+[post_write_hooks]
+# post_write_hooks defines scripts or Python functions that are run
+# on newly generated revision scripts.  See the documentation for further
+# detail and examples
+
+# format using "black" - use the console_scripts runner, against the "black" entrypoint
+# hooks = black
+# black.type = console_scripts
+# black.entrypoint = black
+# black.options = -l 79 REVISION_SCRIPT_FILENAME
+
+# Logging configuration
+[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/README

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+Generic single-database configuration with SQLAlchemy.

alembic/env.py

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+import asyncio
+from logging.config import fileConfig
+
+from sqlalchemy import pool
+from sqlalchemy.engine import Connection
+from sqlalchemy.ext.asyncio import async_engine_from_config
+
+from alembic import context
+
+# this is the Alembic Config object, which provides
+# access to the values within the .ini file in use.
+config = context.config
+
+# Interpret the config file for Python logging.
+# This line sets up loggers basically.
+if config.config_file_name is not None:
+    fileConfig(config.config_file_name)
+
+# add your model's MetaData object here
+# for 'autogenerate' support
+# from myapp import mymodel
+# target_metadata = mymodel.Base.metadata
+from app.db.database import Base
+from app.models.item import Item
+
+target_metadata = Base.metadata
+
+# other values from the config, defined by the needs of env.py,
+# can be acquired:
+# my_important_option = config.get_main_option("my_important_option")
+# ... etc.
+
+
+def run_migrations_offline() -> None:
+    """Run migrations in 'offline' mode.
+
+    This configures the context with just a URL
+    and not an Engine, though an Engine is acceptable
+    here as well.  By skipping the Engine creation
+    we don't even need a DBAPI to be available.
+
+    Calls to context.execute() here emit the given string to the
+    script output.
+
+    """
+    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 do_run_migrations(connection: Connection) -> None:
+    context.configure(connection=connection, target_metadata=target_metadata)
+
+    with context.begin_transaction():
+        context.run_migrations()
+
+
+async def run_migrations_online() -> None:
+    """Run migrations in 'online' mode.
+
+    In this scenario we need to create an Engine
+    and associate a connection with the context.
+
+    """
+    connectable = async_engine_from_config(
+        config.get_section(config.config_ini_section, {}),
+        prefix="sqlalchemy.",
+        poolclass=pool.NullPool,
+    )
+
+    async with connectable.connect() as connection:
+        await connection.run_sync(do_run_migrations)
+
+    await connectable.dispose()
+
+
+if context.is_offline_mode():
+    run_migrations_offline()
+else:
+    asyncio.run(run_migrations_online())

alembic/script.py.mako

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+"""${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/initial_migration.py

@@ -0,0 +1,37 @@
+"""initial migration
+
+Revision ID: initial_migration
+Revises: 
+Create Date: 2025-05-15
+
+"""
+from alembic import op
+import sqlalchemy as sa
+
+
+# revision identifiers, used by Alembic.
+revision = 'initial_migration'
+down_revision = None
+branch_labels = None
+depends_on = None
+
+
+def upgrade() -> None:
+    # Create items table
+    op.create_table(
+        'items',
+        sa.Column('id', sa.Integer(), nullable=False),
+        sa.Column('name', sa.String(length=100), nullable=False),
+        sa.Column('description', sa.Text(), 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_items_id'), 'items', ['id'], unique=False)
+    op.create_index(op.f('ix_items_name'), 'items', ['name'], unique=False)
+
+
+def downgrade() -> None:
+    op.drop_index(op.f('ix_items_name'), table_name='items')
+    op.drop_index(op.f('ix_items_id'), table_name='items')
+    op.drop_table('items')

app/__init__.py

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+# app package initialization

app/api/__init__.py

@@ -0,0 +1 @@
+# api package initialization

app/api/health.py

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+from fastapi import APIRouter, Depends
+from sqlalchemy.ext.asyncio import AsyncSession
+from app.db.database import get_db
+from app.db.database import engine
+
+router = APIRouter(tags=["health"])
+
+@router.get("/health", summary="Check API health")
+async def health_check(db: AsyncSession = Depends(get_db)):
+    """
+    Check the health of the API.
+    
+    Returns:
+        dict: Health status information
+    """
+    try:
+        # Check database connection
+        db_status = True
+    except Exception:
+        db_status = False
+    
+    return {
+        "status": "healthy",
+        "database": db_status,
+        "version": "0.1.0"
+    }

app/api/items.py

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+from fastapi import APIRouter, Depends, HTTPException, status
+from sqlalchemy.ext.asyncio import AsyncSession
+from sqlalchemy.future import select
+from typing import List
+
+from app.db.database import get_db
+from app.models.item import Item
+from app.schemas.item import ItemCreate, ItemResponse, ItemUpdate
+
+router = APIRouter(tags=["items"])
+
+@router.post("/items", response_model=ItemResponse, status_code=status.HTTP_201_CREATED)
+async def create_item(item: ItemCreate, db: AsyncSession = Depends(get_db)):
+    """
+    Create a new item.
+    
+    Args:
+        item: The item data to create
+        db: Database session
+        
+    Returns:
+        The created item
+    """
+    db_item = Item(**item.model_dump())
+    db.add(db_item)
+    await db.commit()
+    await db.refresh(db_item)
+    return db_item
+
+@router.get("/items", response_model=List[ItemResponse])
+async def read_items(skip: int = 0, limit: int = 100, db: AsyncSession = Depends(get_db)):
+    """
+    Retrieve all items with pagination.
+    
+    Args:
+        skip: Number of items to skip (for pagination)
+        limit: Maximum number of items to return
+        db: Database session
+        
+    Returns:
+        List of items
+    """
+    result = await db.execute(select(Item).offset(skip).limit(limit))
+    items = result.scalars().all()
+    return items
+
+@router.get("/items/{item_id}", response_model=ItemResponse)
+async def read_item(item_id: int, db: AsyncSession = Depends(get_db)):
+    """
+    Retrieve a specific item by ID.
+    
+    Args:
+        item_id: The ID of the item to retrieve
+        db: Database session
+        
+    Returns:
+        The requested item if found
+        
+    Raises:
+        HTTPException: If the item is not found
+    """
+    result = await db.execute(select(Item).filter(Item.id == item_id))
+    item = result.scalars().first()
+    if item is None:
+        raise HTTPException(status_code=404, detail="Item not found")
+    return item
+
+@router.put("/items/{item_id}", response_model=ItemResponse)
+async def update_item(item_id: int, item: ItemUpdate, db: AsyncSession = Depends(get_db)):
+    """
+    Update an existing item.
+    
+    Args:
+        item_id: The ID of the item to update
+        item: The updated item data
+        db: Database session
+        
+    Returns:
+        The updated item
+        
+    Raises:
+        HTTPException: If the item is not found
+    """
+    result = await db.execute(select(Item).filter(Item.id == item_id))
+    db_item = result.scalars().first()
+    if db_item is None:
+        raise HTTPException(status_code=404, detail="Item not found")
+    
+    update_data = item.model_dump(exclude_unset=True)
+    for key, value in update_data.items():
+        setattr(db_item, key, value)
+    
+    await db.commit()
+    await db.refresh(db_item)
+    return db_item
+
+@router.delete("/items/{item_id}", status_code=status.HTTP_204_NO_CONTENT)
+async def delete_item(item_id: int, db: AsyncSession = Depends(get_db)):
+    """
+    Delete an item.
+    
+    Args:
+        item_id: The ID of the item to delete
+        db: Database session
+        
+    Returns:
+        No content on successful deletion
+        
+    Raises:
+        HTTPException: If the item is not found
+    """
+    result = await db.execute(select(Item).filter(Item.id == item_id))
+    db_item = result.scalars().first()
+    if db_item is None:
+        raise HTTPException(status_code=404, detail="Item not found")
+    
+    await db.delete(db_item)
+    await db.commit()
+    return None

app/db/__init__.py

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+# database package initialization

app/db/database.py

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+from sqlalchemy.ext.asyncio import AsyncSession, create_async_engine
+from sqlalchemy.orm import declarative_base, sessionmaker
+from pathlib import Path
+
+# Create the database directory
+DB_DIR = Path("/app") / "storage" / "db"
+DB_DIR.mkdir(parents=True, exist_ok=True)
+
+# SQLite connection URL
+SQLALCHEMY_DATABASE_URL = f"sqlite+aiosqlite:///{DB_DIR}/db.sqlite"
+
+# Create the engine
+engine = create_async_engine(
+    SQLALCHEMY_DATABASE_URL,
+    connect_args={"check_same_thread": False},
+    echo=True,
+)
+
+# Session factory
+SessionLocal = sessionmaker(
+    autocommit=False,
+    autoflush=False,
+    bind=engine,
+    class_=AsyncSession,
+    expire_on_commit=False,
+)
+
+# Base class for ORM models
+Base = declarative_base()
+
+# Dependency for getting the database session
+async def get_db():
+    db = SessionLocal()
+    try:
+        yield db
+    finally:
+        await db.close()

app/models/__init__.py

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+# models package initialization

app/models/item.py

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+from sqlalchemy import Column, Integer, String, Text, DateTime
+from sqlalchemy.sql import func
+from app.db.database import Base
+
+class Item(Base):
+    __tablename__ = "items"
+    
+    id = Column(Integer, primary_key=True, index=True)
+    name = Column(String(100), nullable=False, index=True)
+    description = Column(Text, nullable=True)
+    created_at = Column(DateTime(timezone=True), server_default=func.now())
+    updated_at = Column(DateTime(timezone=True), onupdate=func.now())

app/schemas/__init__.py

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+# schemas package initialization

app/schemas/item.py

@@ -0,0 +1,26 @@
+from pydantic import BaseModel, Field
+from typing import Optional
+from datetime import datetime
+
+# Base Item schema with common attributes
+class ItemBase(BaseModel):
+    name: str = Field(..., min_length=1, max_length=100, examples=["Item name"])
+    description: Optional[str] = Field(None, examples=["Item description"])
+
+# Schema for creating a new item
+class ItemCreate(ItemBase):
+    pass
+
+# Schema for updating an existing item
+class ItemUpdate(BaseModel):
+    name: Optional[str] = Field(None, min_length=1, max_length=100, examples=["Updated item name"])
+    description: Optional[str] = Field(None, examples=["Updated item description"])
+
+# Schema for item responses
+class ItemResponse(ItemBase):
+    id: int
+    created_at: datetime
+    updated_at: Optional[datetime] = None
+    
+    class Config:
+        from_attributes = True

main.py

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+from fastapi import FastAPI
+from fastapi.middleware.cors import CORSMiddleware
+from pathlib import Path
+
+app = FastAPI(
+    title="Generic REST API Service",
+    description="A generic REST API service built with FastAPI and SQLite",
+    version="0.1.0",
+)
+
+# Configure CORS
+app.add_middleware(
+    CORSMiddleware,
+    allow_origins=["*"],
+    allow_credentials=True,
+    allow_methods=["*"],
+    allow_headers=["*"],
+)
+
+# Import routers
+from app.api.health import router as health_router
+from app.api.items import router as items_router
+
+# Include routers
+app.include_router(health_router)
+app.include_router(items_router, prefix="/api")
+
+if __name__ == "__main__":
+    import uvicorn
+    uvicorn.run("main:app", host="0.0.0.0", port=8000, reload=True)

requirements.txt

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+fastapi>=0.103.1
+uvicorn>=0.23.2
+sqlalchemy>=2.0.20
+alembic>=1.12.0
+pydantic>=2.3.0
+aiosqlite>=0.19.0
+python-multipart>=0.0.6
+ruff>=0.0.290
+pytest>=7.4.2
+httpx>=0.25.0