Flask SQLAlchemy display queries for debug
If you’re using the Flask-SQLAlchemy extension and don’t want to bother with create_engine, you can set the configuration key SQLALCHEMY_ECHO=True. http://flask-sqlalchemy.pocoo.org/2.1/config/
sqlalchemy
How to create one-to-one relationships with declarative
The documentation explains this nicely: class Parent(Base): __tablename__ = ‘parent’ id = Column(Integer, primary_key=True) child = relationship(“Child”, uselist=False, backref=”parent”) class Child(Base): __tablename__ = ‘child’ id = Column(Integer, primary_key=True) parent_id = Column(Integer, ForeignKey(‘parent.id’)) OR class Parent(Base): __tablename__ = ‘parent’ id = Column(Integer, primary_key=True) child_id = Column(Integer, ForeignKey(‘child.id’)) child = relationship(“Child”, backref=backref(“parent”, uselist=False)) class Child(Base): __tablename__ = … Read more
Flask-SQLAlchemy – Greater than or equal to
You want filter, not filter_by: Invoice.query.filter(Invoice.invoicedate >= date.today()) See this answer for more on filter vs filter_by
Sqlalchemy – Difference between query and query.all in for loops
Nope, there is no difference in DB traffic. The difference is just that for row in session.Query(Model1) does the ORM work on each row when it is about to give it to you, while for row in session.Query(Model1).all() does the ORM work on all rows, before starting to give them to you. Note that q.all() … Read more
SQLAlchemy query to return only n results?
for sqlalchemy >= 1.0.13 Use the limit method. query(Model).filter(something).limit(5).all()