Insert models in the database with SQLAlchemy
Inserting models with SQLAlchemy couldn't be easier! We'll use the db.session1 variable to .add() a model. Let's begin working on our Item resource:
resources/item.py
from sqlalchemy.exc import SQLAlchemyError
from db import db
from models import ItemModel
...
@blp.arguments(ItemSchema)
@blp.response(201, ItemSchema)
def post(self, item_data):
item = ItemModel(**item_data)
try:
db.session.add(item)
db.session.commit()
except SQLAlchemyError:
abort(500, message="An error occurred while inserting the item.")
return item
Similarly in our Store resource:
resources/store.py
from sqlalchemy.exc import SQLAlchemyError, IntegrityError
from db import db
from models import StoreModel
...
@blp.arguments(StoreSchema)
@blp.response(201, StoreSchema)
def post(self, store_data):
store = StoreModel(**store_data)
try:
db.session.add(store)
db.session.commit()
except IntegrityError:
abort(
400,
message="A store with that name already exists.",
)
except SQLAlchemyError:
abort(500, message="An error occurred creating the store.")
return store
Note here we're catching two different errors, IntegrityError for when a client attempts to create a store with a name that already exists, and SQLAlchemyError for anything else.
Since the StoreModel's name column is marked as unique=True, then an IntegrityError is raised when we try to insert another row with the same name.