python - Query One to Many Relationship SQLAlchemy -

i trying query users based upon skills these tables.

class user(usermixin, db.model):     __tablename__ = 'users'      id = db.column(db.integer, primary_key=true)     email = db.column(db.string(64), unique=true, index=true)     username = db.column(db.string(64), unique=true, index=true)     skills = db.relationship('skill', backref='author', lazy='dynamic') 

---

class skill(db.model):     __tablename__ = 'skills'      id = db.column(db.integer, primary_key=true)     skill = db.column(db.string(64), index=true)     author_id = db.column(db.integer, db.foreignkey('users.id')) 

i tried in user table , got error.

@classmethod def users_by_skill(cls, skill):     return user.query.join(skill).filter(skill.skill).all() 

---

attributeerror: 'str' object has no attribute 'skill' 

where missing badly?

you define following class method:

@classmethod def users_by_skill(cls, skill):     return user.query.join(skill).filter(skill.skill).all() 

you expecting use function so:

users = users.users_by_skill('nunchuk') 

that means skill argument in users_by_skill string. then, try use skill.skill, doing 'nunchuk'.skill. python not have skill attribute on string class, hence error.

the filter function takes criteria object. in other words, don't pass value "filter", instead pass criterion represents notion of "the skill column on skill table must equal 'nunchuk'". can using syntax following:

@classmethod def users_by_skill(cls, skill_name):     return user.query.join(skill).filter(skill.skill == skill_name).all()