flask-sqlalchemy

I tried to work with CURD operation using Flask and SQLAlchemy .But getting Error while connecting to database. Here is the Error log. /usr/local/lib/python3.4/dist-packages/flask_sqlalchemy/__init__.py:819: UserWarning: SQLALCHEMY_DATABASE_URI not set. Defaulting to "sqlite:///:memory:". 'SQLALCHEMY_DATABASE_URI not set. Defaulting to ' /usr/local/lib/python3.4/dist-packages/flask_sqlalchemy/__init__.py:839: FSADeprecationWarning: SQLALCHEMY_TRACK_MODIFICATIONS adds significant overhead and will be disabled by default in the future. Set it to True or False to suppress this warning.

My SQLAlchemy models: class Cover(db.Model): # ... a bunch of other fields ... @hybrid_property def number_of_requests(self): if self.requests: return len(self.requests) return 0 @number_of_requests.expression def number_of_requests(cls): return func.count(cls.requests) class Request(db.Model): # ... a bunch of other fields ... # Cover that this request is requesting cover_id = db.Column(db.Integer, db.ForeignKey('cover.id') cover = db.relationship('Cover', backref=backref("requests", cascade="all, delete-orphan")) So, a simple one-to-many relationship between Cover and Request. The number_of

So I'm trying to make an API, using Flask-Restful, but all the examples I find put everything into one app.py file. I found information in the Flask-Restful docs explaining how to structure your API, but it doesn't include anything for using a database. I've posted what I've come up with, and it works if I hard-code some data, but when I import the db into users.py I get an error ImportError: cannot import name 'db' . So, what is the best way to structure an API to bring in your data from a database? Structure myapi run.py api __init__.py resources __init__.py user.py myapi/run.py from api

I have a many to one relationship between the Userownedshare table and the Share table. When I delete a Userownedshare entry from the database I get the following error: AssertionError: Dependency rule tried to blank-out primary key column 'share.ticker' This makes sense as the ticker field in Userownedshare is a Foreign Key in the Share table. However I cannot work out how to fix this error. I think that I want to set up a cascading deletion when a Share entry is orphaned but I cannot work out how to do this, I have read the documentation but I just end up with different types of errors so I

I'm building a Flask website that involves keeping track of payments, and I've run into an issue where I can't really seem to filter one of my db models by date. For instance, if this is what my table looks like: payment_to, amount, due_date (a DateTime object) company A, 3000, 7-20-2018 comapny B, 3000, 7-21-2018 company C, 3000, 8-20-2018 and I want to filter it so that I get all rows that's after July 20th, or all rows that are in August, etc. I can think of a crude, brute-force way to filter all payments and THEN iterate through the list to filter by month/year, but I'd rather stay away

I have two Flask-SQLAlchemy models with a simple one-to-many relationship, like the minimal example below: class School(db.Model): id = db.Column(db.Integer, primary_key=True) name = db.Column(db.String(30)) address = db.Column(db.String(30)) class Teacher(db.Model): id = db.Column(db.Integer, primary_key=True) name = db.Column(db.String(30)) id_school = db.Column(db.Integer, db.ForeignKey(School.id)) school = relationship('School', backref='teachers') Then I add an hybrid property to teacher that uses the relationship, like: @hybrid_property def school_name(self): return self.school.name And

When I'm trying to create a database schema migration, I'm getting this weird error. Can you please help me to figure out what's wrong? $ python app.py db upgrade [skipped] sqlalchemy.exc.ArgumentError: Mapper Mapper|EssayStateAssociations|essay_associations could not assemble any primary key columns for mapped table 'essay_associations' My model: class EssayStateAssociations(db.Model): __tablename__ = 'essay_associations' application_essay_id = db.Column( db.Integer, db.ForeignKey("application_essay.id"), primary_key=True), theme_essay_id = db.Column( db.Integer, db.ForeignKey("theme_essay.id