我在heroku上删除了数据库，但也出现了这个错误：sqlalchemy.exc.OperationalError: (sqlite3.OperationalError) table thesis_have_keywords already exists

Question

我在 heroku 上部署了这段代码，我正在使用 CI/CD 与 travis 和 heroku。出于开发原因，我正在使用 SQLite 数据库。我希望每次在 heroku 上部署 repo 时，数据库将被删除并使用文件数据再次创建。我这样做了，但是 heroku 给了我标题错误。

这是我的代码：

初始化.py:

from flask import Flask
from flask_sqlalchemy import SQLAlchemy
from flask_admin import Admin
import os

db = SQLAlchemy()

def create_app(conf_test=None):
    app = Flask(__name__, instance_relative_config=True)

    print("instance path --- " + os.path.join(app.instance_path, 'database.db'))
    app.config.from_mapping(
        SQLALCHEMY_DATABASE_URI = ''.join(['sqlite:////', os.path.join(app.instance_path, 'database.db')]),
        SQLALCHEMY_TRACK_MODIFICATIONS = os.environ['SQLALCHEMY_TRACK_MODIFICATIONS'],
        JWT_KEY = os.environ['JWT_KEY'],
        SECRET_KEY = os.environ['SECRET_KEY']
    )

    if conf_test is not None:
        app.config.update(conf_test)

    from .model import init_db
    with app.app_context(): init_db()

    from .views import init_views
    with app.app_context(): init_views()

    @app.route("/")
    def hello():
        return "it's working..." 

    return app

模型.py

class CurrentState(enum.Enum):
    available = 'AVAILABLE'
    in_progress = 'IN PROGRESS'
    finished = 'FINISHED'

thesis_have_keywords = db.Table('thesis_have_keywords', 
    db.Column('thesis_id', db.Integer, db.ForeignKey("thesis.id")),
    db.Column('keyword_id', db.Integer, db.ForeignKey("keyword.id"))
)

thesis_have_teaching = db.Table('thesis_have_teaching', 
    db.Column('thesis_id', db.Integer, db.ForeignKey("thesis.id")),
    db.Column('teaching_id', db.Integer, db.ForeignKey("teaching.id"))
)

thesis_have_courses = db.Table('thesis_have_courses', 
    db.Column('thesis_id', db.Integer, db.ForeignKey("thesis.id")),
    db.Column('course_id', db.Integer, db.ForeignKey("degree_courses.id"))
)

class Teacher(db.Model):
    name = db.Column(db.String(50), unique=False, nullable=False)
    surname = db.Column(db.String(50), unique=False, nullable=False)
    mail = db.Column(db.String(100), unique=True, nullable=False)
    id = db.Column(db.String(100), unique=True, nullable=False, primary_key=True)

    thesis = db.relationship("Thesis", back_populates="teacher")


class Thesis(db.Model):
    title = db.Column(db.String(150), unique=True, nullable=False)
    description = db.Column(db.Text, unique=False, nullable=False)
    last_modify = db.Column(db.DateTime(timezone=True), unique=False, nullable=False, default=datetime.datetime.utcnow)
    duration = db.Column(db.Integer, unique=False, nullable=True)
    start_time = db.Column(db.DateTime(timezone=True), unique=False, nullable=True)
    end_time = db.Column(db.DateTime(timezone=True), unique=False, nullable=True)
    current_state = db.Column(db.Enum(CurrentState), unique=False, nullable=False, default=CurrentState('AVAILABLE'))
    id = db.Column(db.Integer, autoincrement=True, primary_key=True)

    teacher_id = db.Column(db.Integer, db.ForeignKey("teacher.id"))
    teacher = db.relationship("Teacher", back_populates="thesis")

    keywords = db.relationship("Keyword", back_populates="thesis", secondary=thesis_have_keywords)

    teaching = db.relationship("Teaching", back_populates="thesis", secondary=thesis_have_teaching)

    courses = db.relationship("DegreeCourses", back_populates="thesis", secondary=thesis_have_courses)

class Keyword(db.Model):
    name = db.Column(db.String(50), unique=True, nullable=False)
    id = db.Column(db.Integer, autoincrement=True, primary_key=True)

    thesis = db.relationship("Thesis", back_populates="keywords", secondary=thesis_have_keywords)

class Teaching(db.Model):
    name = db.Column(db.String(50), unique=False, nullable=False)
    code = db.Column(db.String(100), unique=True, nullable=False)
    id = db.Column(db.Integer, autoincrement=True, primary_key=True) 

    thesis = db.relationship("Thesis", back_populates="teaching", secondary=thesis_have_teaching)

class DegreeCourses(db.Model):
    name = db.Column(db.String(50), unique=False, nullable=False)
    code = db.Column(db.String(100), unique=True, nullable=False)
    _type = db.Column(db.String(20), unique=False, nullable=False)
    id = db.Column(db.Integer, autoincrement=True, primary_key=True)

    thesis = db.relationship("Thesis", back_populates="courses", secondary=thesis_have_courses)

def init_db():
    with current_app.app_context():
        if os.path.exists(current_app.instance_path):
            shutil.rmtree(current_app.instance_path)

        try:
            os.makedirs(current_app.instance_path)
        except OSError:
            pass

        db.init_app(current_app)
        db.drop_all()
        db.session.commit()        
        db.create_all()

        with open("server/teachers.json") as teach_file:
            data = json.load(teach_file)

        teacher_entries=[]
        for teacher in data['teachers']:
            teach = Teacher(name=teacher['name'], surname=teacher['surname'], mail=teacher['mail'], id=teacher['id'])
            teacher_entries.append(teach)

        db.session.add_all(teacher_entries)
        db.session.commit()

每次我删除实例文件夹并重新创建它时。我也尝试只删除数据库文件，但出现同样的错误。

sqlalchemy.exc.OperationalError: (sqlite3.OperationalError) table thesis_have_keywords 已经存在

Answer 1

您将来可能会遇到其他问题（有很好的理由不在 Heroku 上使用 SQLite），但如果您的 database.db 未被跟踪，则不应出现该特定错误。

试试这个：

git rm --cached database.db
git commit -m 'Untrack database'
git push heroku master

请注意，每当您的 dyno 重新启动时，您的数据库都会丢失，happens frequently（至少每天一次，以及每当您部署或更改环境变量或附加组件时）。