sqlalchemy

问题 I have a following query which is using func.group_concat to group some data r = aliased(Rank) t = aliased(Team) p = aliased(Participant) players_ranks_data = ( db.session.query( p, r.id.label('player_team_skill_id'), r.name.label('player_team_skill_name'), func.group_concat(t.name), ) .outerjoin(r, r.id == p.team_skill) .outerjoin(t, t.id == p.team_id) .filter(p.event_id == event_data.id) .filter(p.team_id != '') .group_by('player_team_skill_name') .all() ) When I'm printing what was

问题 I have a following query which is using func.group_concat to group some data r = aliased(Rank) t = aliased(Team) p = aliased(Participant) players_ranks_data = ( db.session.query( p, r.id.label('player_team_skill_id'), r.name.label('player_team_skill_name'), func.group_concat(t.name), ) .outerjoin(r, r.id == p.team_skill) .outerjoin(t, t.id == p.team_id) .filter(p.event_id == event_data.id) .filter(p.team_id != '') .group_by('player_team_skill_name') .all() ) When I'm printing what was

问题 I have tried to implement this code from sqlalchemy import Column, ForeignKey, Integer, String, ForeignKeyConstraint from sqlalchemy_continuum import make_versioned , version_class, parent_class from sqlalchemy.ext.declarative import declarative_base import sqlalchemy as sa params = urllib.parse.quote_plus \ (r'Driver={ODBC Driver 17 for SQL Server};Server=HP;Database=Navigation;Uid=sa;Pwd=<added>;Encrypt=yes;TrustServerCertificate=yes;Connection Timeout=30;') conn_str = 'mssql+pyodbc:///

问题 I have some sqlalchemy that counts rows with the value "3" and then prints out the count. It works fine if the count is 1, 2, 3, etc, but when there are no items, it prints nothing. I wanted it to print 0. So I added an if/else statement that didn't work (it prints nothing, no errors). How would I do this? Here's my current code — not really sure if I should be doing this part in sqlalchemy or python. q = (db.session.query(Article.snippet, sa.func.count(ArticleVote.id)) .join(ArticleVote,

问题 I'm trying to update a row after a select instance = session.query(Scouts).filter(Scouts.camp == camp, Scouts.user == user,Scouts.gender == gender).first() instance.number_of_visits += 1 session.commit() My Scouts class looks like: class Scouts(Base): __tablename__ = 'scouts' camp = Column(String, primary_key=True) user = Column(Integer) gender = Column(String) number_of_visits = Column(Integer) def __init__(self, camp, user, gender, number_of_visits): self.camp = camp self.user = user self

问题 I'm trying to update a row after a select instance = session.query(Scouts).filter(Scouts.camp == camp, Scouts.user == user,Scouts.gender == gender).first() instance.number_of_visits += 1 session.commit() My Scouts class looks like: class Scouts(Base): __tablename__ = 'scouts' camp = Column(String, primary_key=True) user = Column(Integer) gender = Column(String) number_of_visits = Column(Integer) def __init__(self, camp, user, gender, number_of_visits): self.camp = camp self.user = user self

问题 I have a preexisting database that I'm using with SQLAlchemy, so I'm using automap to get the Models from the database. What is the best way to add methods to these classes? For example, for a User class, I'd like to add methods such as verifying the password. Also, I'd like to add methods for flask-login (UserMixin) methods. 回答1: Specify your classes explicitly beforehand, and define your methods as you would normally: Base = automap_base() class User(Base): __tablename__ = 'user' def verify

问题 I have a preexisting database that I'm using with SQLAlchemy, so I'm using automap to get the Models from the database. What is the best way to add methods to these classes? For example, for a User class, I'd like to add methods such as verifying the password. Also, I'd like to add methods for flask-login (UserMixin) methods. 回答1: Specify your classes explicitly beforehand, and define your methods as you would normally: Base = automap_base() class User(Base): __tablename__ = 'user' def verify

问题 I don't understand why I have this error. Please explain the error. I used official documentation. I run Pipenv virtual env: python 3.8.2 sqlalchemy 1.3.16 You can try run this code too. import enum from sqlalchemy import create_engine, Column, Integer, String, Enum from sqlalchemy.ext.declarative import declarative_base from sqlalchemy.orm import sessionmaker engine = create_engine('sqlite:///:memory:', echo=True) Base = declarative_base() Session = sessionmaker(bind=engine) session =

问题 (1366, "Incorrect string value: '\xB4\xEB\xC7\xD1\xB9\xCE...' for column 'VARIABLE_VALUE' at row 484") This error occurs whenever I try to insert a row (for anytable) But I don't have any table which contains 'VARIABLE_VAULE' column. SELECT DISTINCT TABLE_NAME FROM INFORMATION_SCHEMA.COLUMNS WHERE COLUMN_NAME IN ('VARIABLE_VALUE') AND TABLE_SCHEMA='sw'; /* nothing comes up */ How do I locate the table which causes the warning? 回答1: The error happens because you are trying to store an emoji