Advanced Recipe Search

Introduction: Making Recipe Search Smarter

Welcome back! In the last lesson, you learned how to build basic endpoints to retrieve recipes from your database, including fetching a single recipe by its ID and listing recipes with pagination. These are the building blocks of any recipe API. Now, let’s take things a step further. Imagine you open a cooking app and want to find recipes that use only the ingredients you have in your kitchen. Or maybe you want to see the steps of a recipe as a list so you can follow them one by one. These features make your app much more helpful and user-friendly. In this lesson, you’ll learn how to: Search for recipes by a list of ingredients. Return recipe steps as an array, not just a long string. These skills will help you build a smarter, more flexible recipe API .

Quick Model Recap

Before we dive in, let’s quickly remind ourselves how our data is organized. This will help you understand how searching and filtering work. Recipe : Each recipe has an id, a name, a steps field (which is a string with all the steps), and a list of ingredients . Ingredient : Each ingredient has an id and a name . Ingredients are linked to recipes through a many-to-many relationship. Review : Each review is linked to a recipe and has a rating . Here’s a simplified look at the models (using SQLAlchemy): Python from sqlalchemy import Table, Column, Integer, String, Text, ForeignKey from sqlalchemy.orm import relationship, declarative_base Base = declarative_base() recipe_ingredient = Table('recipe_ingredient', Base.metadata, Column('recipe_id', Integer, ForeignKey('recipe.id'), primary_key=True), Column('ingredient_id', Integer, ForeignKey('ingredient.id'), primary_key=True)) class Ingredient(Base):__tablename__ = 'ingredient' id = Column(Integer, primary_key=True) name = Column(String(50)) recipes = relationship('Recipe', secondary=recipe_ingredient, back_populates='ingredients') class Recipe(Base):__tablename__ = 'recipe' id = Column(Integer, primary_key=True) name = Column(String(100)) ingredients = relationship('Ingredient', secondary=recipe_ingredient, back_populates='recipes') steps = Column(Text) The recipe_ingredient table connects recipes and ingredients. Each recipe can have many ingredients, and each ingredient can be used in many recipes. This structure is important for searching recipes by ingredients.

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Python

@router.get("/recipes/{recipe_id}/steps", response_model=StepsOut)
def get_recipe_steps_array(recipe_id: int, db: Session = Depends(get_db)):
    recipe = db.get(Recipe,recipe_id)
    if not recipe:
        raise HTTPException(status_code=404, detail="Recipe not found")

@router.get("/recipes/{recipe_id}/steps", response_model=StepsOut)
def get_recipe_steps_array(recipe_id: int, db: Session = Depends(get_db)):
    recipe = db.get(Recipe,recipe_id)
    if not recipe:
        raise HTTPException(status_code=404, detail="Recipe not found")

Python

    steps_list = []
    if recipe.steps:
        steps_list = [s.strip() for s in recipe.steps.split("\n") if s.strip()]

    steps_list = []
    if recipe.steps:
        steps_list = [s.strip() for s in recipe.steps.split("\n") if s.strip()]

Python

class StepsOut(BaseModel):
    recipe_id: int
    name: Optional[str] = None
    steps: List[str]

class StepsOut(BaseModel):
    recipe_id: int
    name: Optional[str] = None
    steps: List[str]

Python

    return StepsOut(recipe_id=recipe.id, name=recipe.name, steps=steps_list)

    return StepsOut(recipe_id=recipe.id, name=recipe.name, steps=steps_list)

JSON

{
  "recipe_id": 2,
  "name": "Tomato Basil Soup",
  "steps": [
    "Chop tomatoes.",
    "Add basil.",
    "Simmer for 20 minutes."
  ]
}

{
  "recipe_id": 2,
  "name": "Tomato Basil Soup",
  "steps": [
    "Chop tomatoes.",
    "Add basil.",
    "Simmer for 20 minutes."
  ]
}

Python

@router.post("/recipes/by-ingredients", response_model=List[RecipeOut])
def get_recipes_by_ingredients(payload: IngredientsIn, db: Session = Depends(get_db)):
    if not payload.ingredients:
        raise HTTPException(status_code=400, detail='Missing "ingredients" in request')

    ingredient_names = [name.strip().lower() for name in payload.ingredients if name.strip()]
    if not ingredient_names:
        raise HTTPException(status_code=400, detail="Empty ingredients list")

@router.post("/recipes/by-ingredients", response_model=List[RecipeOut])
def get_recipes_by_ingredients(payload: IngredientsIn, db: Session = Depends(get_db)):
    if not payload.ingredients:
        raise HTTPException(status_code=400, detail='Missing "ingredients" in request')

    ingredient_names = [name.strip().lower() for name in payload.ingredients if name.strip()]
    if not ingredient_names:
        raise HTTPException(status_code=400, detail="Empty ingredients list")

JSON

{
  "ingredients": ["Tomato", "Basil"]
}

{
  "ingredients": ["Tomato", "Basil"]
}

Python

    # Find all matching ingredients (case-insensitive)
    ingredient_objs = db.query(Ingredient).filter(func.lower(Ingredient.name).in_(ingredient_names)).all()
    ingredient_ids = [i.id for i in ingredient_objs]
    if not ingredient_ids:
        return []

    # Find all matching ingredients (case-insensitive)
    ingredient_objs = db.query(Ingredient).filter(func.lower(Ingredient.name).in_(ingredient_names)).all()
    ingredient_ids = [i.id for i in ingredient_objs]
    if not ingredient_ids:
        return []

Python

    subq = (
        db.query(
            recipe_ingredient.c.recipe_id.label("recipe_id"),
            func.count(func.distinct(func.lower(Ingredient.name))).label("match_count"),
        )
        .join(Ingredient, recipe_ingredient.c.ingredient_id == Ingredient.id)
        .filter(func.lower(Ingredient.name).in_(ingredient_names))
        .group_by(recipe_ingredient.c.recipe_id)
        .subquery()
    )

    recipes = (
        db.query(Recipe)
        .join(subq, Recipe.id == subq.c.recipe_id)
        .filter(subq.c.match_count == len(ingredient_names))
        .all()
    )

    subq = (
        db.query(
            recipe_ingredient.c.recipe_id.label("recipe_id"),
            func.count(func.distinct(func.lower(Ingredient.name))).label("match_count"),
        )
        .join(Ingredient, recipe_ingredient.c.ingredient_id == Ingredient.id)
        .filter(func.lower(Ingredient.name).in_(ingredient_names))
        .group_by(recipe_ingredient.c.recipe_id)
        .subquery()
    )

    recipes = (
        db.query(Recipe)
        .join(subq, Recipe.id == subq.c.recipe_id)
        .filter(subq.c.match_count == len(ingredient_names))
        .all()
    )

Python

class RecipeOut(BaseModel):
    id: int
    name: Optional[str] = None
    ingredients: List[str] = []
    steps: Optional[str] = None

class RecipeOut(BaseModel):
    id: int
    name: Optional[str] = None
    ingredients: List[str] = []
    steps: Optional[str] = None

Python

def serialize_recipe(recipe: Recipe) -> RecipeOut:
    return RecipeOut(
        id=recipe.id,
        name=recipe.name,
        ingredients=[i.name for i in recipe.ingredients],
        steps=recipe.steps,
    )

def serialize_recipe(recipe: Recipe) -> RecipeOut:
    return RecipeOut(
        id=recipe.id,
        name=recipe.name,
        ingredients=[i.name for i in recipe.ingredients],
        steps=recipe.steps,
    )

Python

    return [serialize_recipe(r) for r in recipes]

    return [serialize_recipe(r) for r in recipes]

JSON

[
  {
    "id": 2,
    "name": "Tomato Basil Soup",
    "ingredients": ["Tomato", "Basil", "Garlic"],
    "steps": "Chop tomatoes...\nAdd basil..."
  }
]

[
  {
    "id": 2,
    "name": "Tomato Basil Soup",
    "ingredients": ["Tomato", "Basil", "Garlic"],
    "steps": "Chop tomatoes...\nAdd basil..."
  }
]

Python

@router.get("/recipes/{recipe_id}/steps", response_model=StepsOut)
def get_recipe_steps_array(recipe_id: int, db: Session = Depends(get_db)):
    recipe = db.get(Recipe,recipe_id)
    if not recipe:
        raise HTTPException(status_code=404, detail="Recipe not found")

Python

    steps_list = []
    if recipe.steps:
        steps_list = [s.strip() for s in recipe.steps.split("\n") if s.strip()]

Python

class StepsOut(BaseModel):
    recipe_id: int
    name: Optional[str] = None
    steps: List[str]

Python

    return StepsOut(recipe_id=recipe.id, name=recipe.name, steps=steps_list)

JSON

{
  "recipe_id": 2,
  "name": "Tomato Basil Soup",
  "steps": [
    "Chop tomatoes.",
    "Add basil.",
    "Simmer for 20 minutes."
  ]
}

Python

@router.post("/recipes/by-ingredients", response_model=List[RecipeOut])
def get_recipes_by_ingredients(payload: IngredientsIn, db: Session = Depends(get_db)):
    if not payload.ingredients:
        raise HTTPException(status_code=400, detail='Missing "ingredients" in request')

    ingredient_names = [name.strip().lower() for name in payload.ingredients if name.strip()]
    if not ingredient_names:
        raise HTTPException(status_code=400, detail="Empty ingredients list")

JSON

{
  "ingredients": ["Tomato", "Basil"]
}

Python

    # Find all matching ingredients (case-insensitive)
    ingredient_objs = db.query(Ingredient).filter(func.lower(Ingredient.name).in_(ingredient_names)).all()
    ingredient_ids = [i.id for i in ingredient_objs]
    if not ingredient_ids:
        return []

Python

    subq = (
        db.query(
            recipe_ingredient.c.recipe_id.label("recipe_id"),
            func.count(func.distinct(func.lower(Ingredient.name))).label("match_count"),
        )
        .join(Ingredient, recipe_ingredient.c.ingredient_id == Ingredient.id)
        .filter(func.lower(Ingredient.name).in_(ingredient_names))
        .group_by(recipe_ingredient.c.recipe_id)
        .subquery()
    )

    recipes = (
        db.query(Recipe)
        .join(subq, Recipe.id == subq.c.recipe_id)
        .filter(subq.c.match_count == len(ingredient_names))
        .all()
    )

Python

class RecipeOut(BaseModel):
    id: int
    name: Optional[str] = None
    ingredients: List[str] = []
    steps: Optional[str] = None

Python

def serialize_recipe(recipe: Recipe) -> RecipeOut:
    return RecipeOut(
        id=recipe.id,
        name=recipe.name,
        ingredients=[i.name for i in recipe.ingredients],
        steps=recipe.steps,
    )

Python

    return [serialize_recipe(r) for r in recipes]

JSON

[
  {
    "id": 2,
    "name": "Tomato Basil Soup",
    "ingredients": ["Tomato", "Basil", "Garlic"],
    "steps": "Chop tomatoes...\nAdd basil..."
  }
]

Introduction: Making Recipe Search Smarter

Quick Model Recap

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Returning Recipe Steps as an Array

Step 1: Fetching the Recipe

Step 2: Splitting the Steps String

Step 3: Returning the Steps as a List

Retrieving Recipes by Ingredients

Step 1: Accepting the Ingredient List

Step 2: Finding Matching Ingredient IDs

Step 3: Finding Recipes That Use All Ingredients

Step 4: Returning the Results

Review And What’s Next