Create simple todo app with FastAPI and SQLite

README.md

@@ -1,3 +1,69 @@
-# FastAPI Application
+# Simple Todo Application
 
-This is a FastAPI application bootstrapped by BackendIM, the AI-powered backend generation platform.
+A simple Todo API built with FastAPI and SQLite.
+
+## Features
+
+- Create, Read, Update, and Delete Todo items
+- SQLite database with SQLAlchemy ORM
+- Database migrations with Alembic
+- API documentation with Swagger UI and ReDoc
+- Health check endpoint
+
+## Project Structure
+
+```
+/
+├── app/                    # Main application package
+│   ├── api/                # API endpoints
+│   │   ├── health.py       # Health check endpoint
+│   │   ├── schemas.py      # Pydantic models
+│   │   └── todos.py        # Todo CRUD endpoints
+│   ├── database/           # Database configuration
+│   │   └── config.py       # SQLAlchemy setup
+│   └── models/             # SQLAlchemy models
+│       └── todo.py         # Todo model
+├── migrations/             # Alembic migrations
+│   └── versions/           # Migration scripts
+├── alembic.ini             # Alembic configuration
+├── main.py                 # Application entry point
+└── requirements.txt        # Python dependencies
+```
+
+## API Endpoints
+
+- `GET /api/todos`: Get all todo items
+- `POST /api/todos`: Create a new todo item
+- `GET /api/todos/{todo_id}`: Get a specific todo item
+- `PUT /api/todos/{todo_id}`: Update a todo item
+- `DELETE /api/todos/{todo_id}`: Delete a todo item
+- `GET /health`: Check application health
+
+## Getting Started
+
+### Prerequisites
+
+- Python 3.8 or higher
+
+### Installation
+
+1. Clone the repository
+2. Install dependencies:
+   ```
+   pip install -r requirements.txt
+   ```
+3. Run the application:
+   ```
+   uvicorn main:app --reload
+   ```
+
+### API Documentation
+
+Once the application is running, you can access the API documentation at:
+
+- Swagger UI: http://localhost:8000/docs
+- ReDoc: http://localhost:8000/redoc
+
+## Database
+
+The application uses SQLite as the database with SQLAlchemy ORM. The database file is stored at `/app/storage/db/db.sqlite`.

alembic.ini

@@ -0,0 +1,84 @@
+# A generic, single database configuration.
+
+[alembic]
+# path to migration scripts
+script_location = migrations
+
+# template used to generate migration files
+# file_template = %%(rev)s_%%(slug)s
+
+# 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 migrations/versions.  When using multiple version
+# directories, initial revisions must be specified with --version-path
+# version_locations = %(here)s/bar %(here)s/bat migrations/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
+
+# 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

app/api/health.py

@@ -0,0 +1,18 @@
+from fastapi import APIRouter, Depends
+from sqlalchemy.orm import Session
+from app.database.config import get_db
+
+router = APIRouter()
+
+
+@router.get("/health")
+def health_check(db: Session = Depends(get_db)):
+    """
+    Health check endpoint that verifies the API and database connection are working
+    """
+    try:
+        # Test database connection
+        db.execute("SELECT 1")
+        return {"status": "healthy", "database": "connected"}
+    except Exception as e:
+        return {"status": "unhealthy", "database": "disconnected", "error": str(e)}

app/api/schemas.py

@@ -0,0 +1,29 @@
+from pydantic import BaseModel
+from datetime import datetime
+from typing import Optional
+
+
+class TodoBase(BaseModel):
+    title: str
+    description: Optional[str] = None
+    completed: bool = False
+
+
+class TodoCreate(TodoBase):
+    pass
+
+
+class TodoUpdate(BaseModel):
+    title: Optional[str] = None
+    description: Optional[str] = None
+    completed: Optional[bool] = None
+
+
+class TodoResponse(TodoBase):
+    id: int
+    created_at: datetime
+    updated_at: datetime
+
+    class Config:
+        orm_mode = True
+        from_attributes = True

app/api/todos.py

@@ -0,0 +1,62 @@
+from fastapi import APIRouter, Depends, HTTPException, status
+from sqlalchemy.orm import Session
+from typing import List
+from app.database.config import get_db
+from app.models.todo import Todo
+from app.api.schemas import TodoCreate, TodoResponse, TodoUpdate
+
+router = APIRouter()
+
+
+@router.post("/", response_model=TodoResponse, status_code=status.HTTP_201_CREATED)
+def create_todo(todo: TodoCreate, db: Session = Depends(get_db)):
+    """Create a new todo item"""
+    db_todo = Todo(**todo.dict())
+    db.add(db_todo)
+    db.commit()
+    db.refresh(db_todo)
+    return db_todo
+
+
+@router.get("/", response_model=List[TodoResponse])
+def read_todos(skip: int = 0, limit: int = 100, db: Session = Depends(get_db)):
+    """Get all todo items"""
+    todos = db.query(Todo).offset(skip).limit(limit).all()
+    return todos
+
+
+@router.get("/{todo_id}", response_model=TodoResponse)
+def read_todo(todo_id: int, db: Session = Depends(get_db)):
+    """Get a specific todo item by ID"""
+    db_todo = db.query(Todo).filter(Todo.id == todo_id).first()
+    if db_todo is None:
+        raise HTTPException(status_code=404, detail="Todo not found")
+    return db_todo
+
+
+@router.put("/{todo_id}", response_model=TodoResponse)
+def update_todo(todo_id: int, todo: TodoUpdate, db: Session = Depends(get_db)):
+    """Update a todo item"""
+    db_todo = db.query(Todo).filter(Todo.id == todo_id).first()
+    if db_todo is None:
+        raise HTTPException(status_code=404, detail="Todo not found")
+
+    update_data = todo.dict(exclude_unset=True)
+    for key, value in update_data.items():
+        setattr(db_todo, key, value)
+
+    db.commit()
+    db.refresh(db_todo)
+    return db_todo
+
+
+@router.delete("/{todo_id}", status_code=status.HTTP_204_NO_CONTENT)
+def delete_todo(todo_id: int, db: Session = Depends(get_db)):
+    """Delete a todo item"""
+    db_todo = db.query(Todo).filter(Todo.id == todo_id).first()
+    if db_todo is None:
+        raise HTTPException(status_code=404, detail="Todo not found")
+
+    db.delete(db_todo)
+    db.commit()
+    return None

app/database/config.py

@@ -0,0 +1,27 @@
+from pathlib import Path
+from sqlalchemy import create_engine
+from sqlalchemy.ext.declarative import declarative_base
+from sqlalchemy.orm import sessionmaker
+
+# Create the database directory
+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)
+
+Base = declarative_base()
+
+
+# Dependency
+def get_db():
+    db = SessionLocal()
+    try:
+        yield db
+    finally:
+        db.close()

app/models/todo.py

@@ -0,0 +1,14 @@
+from sqlalchemy import Column, Integer, String, Boolean, DateTime
+from sqlalchemy.sql import func
+from app.database.config import Base
+
+
+class Todo(Base):
+    __tablename__ = "todos"
+
+    id = Column(Integer, primary_key=True, index=True)
+    title = Column(String, index=True)
+    description = Column(String, nullable=True)
+    completed = Column(Boolean, default=False)
+    created_at = Column(DateTime, default=func.now())
+    updated_at = Column(DateTime, default=func.now(), onupdate=func.now())

main.py

@@ -0,0 +1,17 @@
+import uvicorn
+from fastapi import FastAPI
+from app.api.todos import router as todos_router
+from app.api.health import router as health_router
+
+app = FastAPI(
+    title="Todo API",
+    description="A simple TODO API built with FastAPI and SQLite",
+    version="0.1.0",
+)
+
+# Include routers
+app.include_router(todos_router, prefix="/api/todos", tags=["todos"])
+app.include_router(health_router, tags=["health"])
+
+if __name__ == "__main__":
+    uvicorn.run("main:app", host="0.0.0.0", port=8000, reload=True)

migrations/env.py

@@ -0,0 +1,77 @@
+from logging.config import fileConfig
+
+from sqlalchemy import engine_from_config
+from sqlalchemy import pool
+
+from alembic import context
+from app.database.config import Base
+
+# Import all models here so they're recognized by alembic
+from app.models.todo import Todo  # noqa: F401
+
+# 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.
+fileConfig(config.config_file_name)
+
+# add your model's MetaData object here
+# for 'autogenerate' support
+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():
+    """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 run_migrations_online():
+    """Run migrations in 'online' mode.
+
+    In this scenario we need to create an Engine
+    and associate a connection with the context.
+
+    """
+    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()

migrations/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():
+    ${upgrades if upgrades else "pass"}
+
+
+def downgrade():
+    ${downgrades if downgrades else "pass"}

migrations/versions/initial_migration.py

@@ -0,0 +1,41 @@
+"""initial migration
+
+Revision ID: 001
+Revises:
+Create Date: 2023-08-20
+
+"""
+
+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():
+    # Create todos table
+    op.create_table(
+        "todos",
+        sa.Column("id", sa.Integer(), nullable=False),
+        sa.Column("title", sa.String(), nullable=False),
+        sa.Column("description", sa.String(), nullable=True),
+        sa.Column("completed", sa.Boolean(), default=False),
+        sa.Column("created_at", sa.DateTime(), default=sa.func.now()),
+        sa.Column(
+            "updated_at", sa.DateTime(), default=sa.func.now(), onupdate=sa.func.now()
+        ),
+        sa.PrimaryKeyConstraint("id"),
+    )
+    op.create_index(op.f("ix_todos_id"), "todos", ["id"], unique=False)
+    op.create_index(op.f("ix_todos_title"), "todos", ["title"], unique=False)
+
+
+def downgrade():
+    op.drop_index(op.f("ix_todos_title"), table_name="todos")
+    op.drop_index(op.f("ix_todos_id"), table_name="todos")
+    op.drop_table("todos")

requirements.txt

@@ -0,0 +1,8 @@
+fastapi==0.104.1
+pydantic==2.4.2
+sqlalchemy==2.0.23
+alembic==1.12.1
+uvicorn==0.23.2
+ruff==0.1.6
+python-dotenv==1.0.0
+pathlib==1.0.1