Implement Number Divisibility API with FastAPI and SQLite

README.md

@@ -5,6 +5,9 @@ A simple REST API built with FastAPI that checks if a number is divisible by 2.
 ## Features
 
 - Check if a number is divisible by 2 via GET or POST requests
+- History endpoint to view all past checks
+- Database integration with SQLAlchemy and SQLite
+- Database migrations managed by Alembic
 - Health endpoint for monitoring
 - OpenAPI documentation built-in
 
@@ -48,6 +51,28 @@ Check if a number is divisible by 2 using a JSON request body.
 }
 ```
 
+### GET /history
+
+Get the history of all divisibility checks performed.
+
+**Response:**
+```json
+[
+  {
+    "number": 42,
+    "is_divisible_by_2": true,
+    "id": 1,
+    "created_at": "2025-05-14T12:34:56.789Z"
+  },
+  {
+    "number": 7,
+    "is_divisible_by_2": false,
+    "id": 2,
+    "created_at": "2025-05-14T12:35:01.234Z"
+  }
+]
+```
+
 ### GET /health
 
 Health check endpoint to verify the API is running.
@@ -68,6 +93,10 @@ Health check endpoint to verify the API is running.
    ```
    pip install -r requirements.txt
    ```
+3. Run database migrations:
+   ```
+   alembic upgrade head
+   ```
 
 ## Running the API
 

alembic.ini

@@ -0,0 +1,101 @@
+# 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.
+# If specified, requires the python-dateutil library that can be
+# installed by adding `alembic[tz]` to the pip requirements
+# 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.
+# The path separator used here should be the separator specified by "version_path_separator" below.
+# version_locations = %(here)s/bar:%(here)s/bat:alembic/versions
+
+# version path separator; As mentioned above, this is the character used to split
+# version_locations. The default within new alembic.ini files is "os", which uses os.pathsep.
+# If this key is omitted entirely, it falls back to the legacy behavior of splitting on spaces and/or commas.
+# Valid values for version_path_separator are:
+#
+# version_path_separator = :
+# version_path_separator = ;
+# version_path_separator = space
+version_path_separator = os  # Use os.pathsep. Default configuration used for new projects.
+
+# 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/env.py

@@ -0,0 +1,79 @@
+from logging.config import fileConfig
+
+from sqlalchemy import engine_from_config
+from sqlalchemy import pool
+
+from alembic import context
+from app.database.connection import Base
+
+# Import models to register with SQLAlchemy metadata
+# This import is needed even though it appears unused
+import app.models.number  # 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.
+if config.config_file_name is not None:
+    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() -> 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 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 = 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 +1,39 @@
+"""Initial migration
+
+Revision ID: 001
+Revises:
+Create Date: 2025-05-14
+
+"""
+
+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 number_checks table
+    op.create_table(
+        "number_checks",
+        sa.Column("id", sa.Integer(), nullable=False),
+        sa.Column("number", sa.Integer(), nullable=False),
+        sa.Column("is_divisible_by_2", sa.Boolean(), nullable=False),
+        sa.Column(
+            "created_at",
+            sa.DateTime(timezone=True),
+            server_default=sa.text("(CURRENT_TIMESTAMP)"),
+        ),
+        sa.PrimaryKeyConstraint("id"),
+    )
+    op.create_index(op.f("ix_number_checks_id"), "number_checks", ["id"], unique=False)
+
+
+def downgrade() -> None:
+    op.drop_index(op.f("ix_number_checks_id"), table_name="number_checks")
+    op.drop_table("number_checks")

app/__init__.py

@@ -0,0 +1 @@
+# App package

app/api/endpoints.py

@@ -0,0 +1,88 @@
+from fastapi import APIRouter, Path as PathParam, Depends
+from sqlalchemy.orm import Session
+from typing import List
+
+from app.database.connection import get_db
+from app.models.number import NumberCheck
+from app.schemas.number import NumberRequest, DivisibilityResponse, NumberCheckResponse
+
+router = APIRouter()
+
+
+@router.get("/", summary="API Root")
+def read_root():
+    """Welcome message for the API."""
+    return {"message": "Welcome to the Number Divisibility API"}
+
+
+@router.get(
+    "/divisibility/{number}",
+    response_model=DivisibilityResponse,
+    summary="Check divisibility (GET)",
+)
+def check_divisibility(
+    number: int = PathParam(..., description="The number to check divisibility for"),
+    db: Session = Depends(get_db),
+):
+    """
+    Check if a number is divisible by 2.
+
+    Returns a JSON response with the number and a boolean indicating if it's divisible by 2.
+    """
+    is_divisible = number % 2 == 0
+
+    # Log the check in the database
+    number_check = NumberCheck(number=number, is_divisible_by_2=is_divisible)
+    db.add(number_check)
+    db.commit()
+    db.refresh(number_check)
+
+    return {"number": number, "is_divisible_by_2": is_divisible}
+
+
+@router.post(
+    "/divisibility",
+    response_model=DivisibilityResponse,
+    summary="Check divisibility (POST)",
+)
+def check_divisibility_post(request: NumberRequest, db: Session = Depends(get_db)):
+    """
+    Check if a number is divisible by 2 using POST request.
+
+    Returns a JSON response with the number and a boolean indicating if it's divisible by 2.
+    """
+    is_divisible = request.number % 2 == 0
+
+    # Log the check in the database
+    number_check = NumberCheck(number=request.number, is_divisible_by_2=is_divisible)
+    db.add(number_check)
+    db.commit()
+    db.refresh(number_check)
+
+    return {"number": request.number, "is_divisible_by_2": is_divisible}
+
+
+@router.get(
+    "/history", response_model=List[NumberCheckResponse], summary="Check history"
+)
+def get_check_history(db: Session = Depends(get_db)):
+    """
+    Get the history of number divisibility checks.
+
+    Returns a list of all number checks.
+    """
+    return db.query(NumberCheck).all()
+
+
+@router.get("/health", summary="Health check")
+def health_check():
+    """
+    Health check endpoint to verify the API is running.
+
+    Returns a JSON response with status information.
+    """
+    return {
+        "status": "healthy",
+        "api_version": "1.0.0",
+        "service": "Number Divisibility API",
+    }

app/database/__init__.py

@@ -0,0 +1,3 @@
+from app.database.connection import Base, engine, get_db
+
+__all__ = ["Base", "engine", "get_db"]

app/database/connection.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 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/__init__.py

@@ -0,0 +1,3 @@
+from app.models.number import NumberCheck
+
+__all__ = ["NumberCheck"]

app/models/number.py

@@ -0,0 +1,12 @@
+from sqlalchemy import Column, Integer, Boolean, DateTime
+from sqlalchemy.sql import func
+from app.database.connection import Base
+
+
+class NumberCheck(Base):
+    __tablename__ = "number_checks"
+
+    id = Column(Integer, primary_key=True, index=True)
+    number = Column(Integer, nullable=False)
+    is_divisible_by_2 = Column(Boolean, nullable=False)
+    created_at = Column(DateTime(timezone=True), server_default=func.now())

app/schemas/__init__.py

@@ -0,0 +1 @@
+# Schema package

app/schemas/number.py

@@ -0,0 +1,18 @@
+from pydantic import BaseModel, ConfigDict
+from datetime import datetime
+
+
+class NumberRequest(BaseModel):
+    number: int
+
+
+class DivisibilityResponse(BaseModel):
+    number: int
+    is_divisible_by_2: bool
+
+
+class NumberCheckResponse(DivisibilityResponse):
+    id: int
+    created_at: datetime
+
+    model_config = ConfigDict(from_attributes=True)

main.py

@@ -1,58 +1,18 @@
-from fastapi import FastAPI, HTTPException, Path as PathParam
-from pydantic import BaseModel
-from pathlib import Path
+from fastapi import FastAPI
+from app.api.endpoints import router
+from app.database.connection import Base, engine
+
+# Create the database tables
+Base.metadata.create_all(bind=engine)
 
 # Create the FastAPI app
 app = FastAPI(
     title="Number Divisibility API",
     description="A simple API to check if a number is divisible by 2",
-    version="1.0.0"
+    version="1.0.0",
+    docs_url="/docs",
+    redoc_url="/redoc",
 )
 
-class NumberRequest(BaseModel):
-    number: int
-
-class DivisibilityResponse(BaseModel):
-    number: int
-    is_divisible_by_2: bool
-
-@app.get("/")
-def read_root():
-    return {"message": "Welcome to the Number Divisibility API"}
-
-@app.get("/divisibility/{number}", response_model=DivisibilityResponse)
-def check_divisibility(number: int = PathParam(..., description="The number to check divisibility for")):
-    """
-    Check if a number is divisible by 2.
-    
-    Returns a JSON response with the number and a boolean indicating if it's divisible by 2.
-    """
-    return {
-        "number": number,
-        "is_divisible_by_2": number % 2 == 0
-    }
-
-@app.post("/divisibility", response_model=DivisibilityResponse)
-def check_divisibility_post(request: NumberRequest):
-    """
-    Check if a number is divisible by 2 using POST request.
-    
-    Returns a JSON response with the number and a boolean indicating if it's divisible by 2.
-    """
-    return {
-        "number": request.number,
-        "is_divisible_by_2": request.number % 2 == 0
-    }
-
-@app.get("/health")
-def health_check():
-    """
-    Health check endpoint to verify the API is running.
-    
-    Returns a JSON response with status information.
-    """
-    return {
-        "status": "healthy",
-        "api_version": app.version,
-        "service": "Number Divisibility API"
-    }
+# Include the router
+app.include_router(router)

requirements.txt

@@ -1,3 +1,6 @@
 fastapi==0.104.1
 uvicorn==0.23.2
-pydantic==2.4.2
+pydantic==2.4.2
+sqlalchemy==2.0.23
+alembic==1.12.1
+ruff==0.1.5