Flask-SQLAlchemy No Application Found Runtime Error-CodePudding

I'm using Flask-SQLAlchemy to represent a Student. I'm getting a Runtime error when querying my Student object. I've referenced previous posts about this issue, but can't seem to fix it.

Here is my Student class:

class Student(db.Model):
    __tablename__ = 'students'
    id = db.Column(db.Integer(), primary_key=True)
    last_name = db.Column(db.Text(), nullable=False)
    first_name = db.Column(db.Text(), nullable=False)
    major_1 = db.Column(db.Text(), nullable=False)
    major_2 = db.Column(db.Text())
    major_3 = db.Column(db.Text())
    concentration_1 = db.Column(db.Text())
    concentration_2 = db.Column(db.Text())
    concentration_3 = db.Column(db.Text())
    minor_1 = db.Column(db.Text())
    minor_2 = db.Column(db.Text())
    minor_3 = db.Column(db.Text())
    math_placement_score = db.Column(db.Integer())
    high_school_gpa = db.Column(db.Float(), 
        db.CheckConstraint('high_school_gpa >= 0.0 AND high_school_gpa <= 4.0'))
    college_gpa = db.Column(db.Float(), 
        db.CheckConstraint('high_school_gpa >= 0.0 AND high_school_gpa <= 4.0'))
    sat_score = db.Column(db.Integer(), 
        db.CheckConstraint(f'sat_score >= {app.config["SAT_SCORE_MIN"]} AND sat_score <= {app.config["SAT_SCORE_MAX"]}'))
    act_score = db.Column(db.Integer(), 
        db.CheckConstraint(f'sat_score >= {app.config["ACT_SCORE_MIN"]} AND sat_score <= {app.config["ACT_SCORE_MAX"]}'))
    state_code = db.Column(db.Text(), nullable=False)
    country_code = db.Column(db.Text(), nullable=False)
    leave_date = db.Column(db.DateTime())
    first_gen_student = db.Column(db.Boolean())


    @staticmethod
    def gen_random_id():
        print(Student.query.all()) # This errors out.

Here is where I initialize the models:

# Init the DB, create all tables.
db.init_app(app)
from app.models import User, Student
with app.app_context():
    db.create_all()

Here is the error stack: Error Stack

When I call the gen_random_id() function, the error occurs. Any ideas on how to fix?

CodePudding user response：

I ended up figuring out a fix.

If you define your db object as:

db = SQLAlchemy()

then no context is assigned.

If you define your db object as:

db = SQLAlchemy(app)

then it will assign the correct context.