我正在创建一个应用程序来替换浏览器中的当前选项卡管理器。 我在groups-table Topic和tabs-table Tab之间创建了一个简单的一对多关系。 我希望能够自动删除主题的孩子,如果我删除它。 这是我目前拥有的:
from flask import request, redirect, url_for, render_template, Flask
from flask_sqlalchemy import SQLAlchemy
from sqlalchemy import exc
from flask_whooshee import Whooshee
from datetime import datetime
app = Flask(__name__)
app.config['SQLALCHEMY_DATABASE_URI'] = 'sqlite:///database.db'
app.config['SQLALCHEMY_TRACK_MODIFICATIONS'] = False
db = SQLAlchemy(app)
whooshee = Whooshee(app)
@whooshee.register_model('topic_name')
class Topic(db.Model):
__tablename__ = 'topic'
id = db.Column(db.Integer, primary_key=True, autoincrement=True)
topic_name = db.Column(db.String, unique=True, nullable=False)
topic_created = db.Column(db.DateTime, default=datetime.utcnow)
topic_changed = db.Column(db.DateTime, default=datetime.utcnow)
topic_tabs = db.relationship('Tab', backref='topic', cascade='all, delete-orphan', lazy='dynamic')
@whooshee.register_model('tab_name', 'tab_link', 'tab_description')
class Tab(db.Model):
__tablename__ = 'tab'
id = db.Column(db.Integer, primary_key=True, autoincrement=True)
tab_name = db.Column(db.String, nullable=False)
tab_link = db.Column(db.String, unique=True, nullable=False)
tab_favicon = db.Column(db.String)
tab_description = db.Column(db.String)
tab_created = db.Column(db.DateTime, default=datetime.utcnow)
tab_changed = db.Column(db.DateTime, default=datetime.utcnow)
topic_id = db.Column(db.Integer, db.ForeignKey('topic.id'))
@app.route('/', methods=['GET'])
def index():
return "Test"
if __name__ == '__main__':
db.create_all()
try:
db.session.commit()
except exc.IntegrityError as e:
print(str(e))
db.session.rollback()
top = Topic(topic_name='Test')
db.session.add(top)
try:
db.session.commit()
except exc.IntegrityError as e:
print(str(e))
db.session.rollback()
top2 = Topic(topic_name='Test2')
db.session.add(top2)
try:
db.session.commit()
except exc.IntegrityError as e:
print(str(e))
db.session.rollback()
t1 = Tab(tab_name='t1', tab_link='t1l', tab_favicon='t1f', tab_description='t1d', topic_id=top.id)
t2 = Tab(tab_name='t2', tab_link='t2l', tab_favicon='t2f', tab_description='t2d', topic_id=top.id)
t3 = Tab(tab_name='t3', tab_link='t3l', tab_favicon='t3f', tab_description='t3d', topic_id=top.id)
db.session.add(t1)
db.session.add(t2)
db.session.add(t3)
try:
db.session.commit()
except exc.IntegrityError as e:
print(str(e))
db.session.rollback()
import uuid
app.secret_key = str(uuid.uuid4())
app.run(debug=True)
问题是我得到完整性错误,当我试图在数据库中添加某些东西时,我不确定可能会出错。 如果我停止服务器,我也想将以前的记录保存在数据库中,我该如何实现呢?
UPD:即使我完全删除了我的数据库,也会发生以下行为。 我在一个空文件夹中简单地运行脚本python script_name.py
后得到这个错误。
UPD2:如果有人需要检查数据库是否存在,有一个特殊的帮助函数https://sqlalchemy-utils.readthedocs.io/en/latest/database_helpers.html#database-exists
(sqlite3.IntegrityError)UNIQUE constraint failed:主题。topic_name[SQL:'INSERT INTO topic(topic_name,topic_created,topic_changed)VALUES(?, ?, ?)'][参数:('测试', '2018-09-03 05:21:08.728564', '2018-09-03 05:21:08.728564')] (此错误的背景:http://sqlalche.me/e/gkpj)
(sqlite3.IntegrityError)UNIQUE constraint failed:主题。topic_name[SQL:'INSERT INTO topic(topic_name,topic_created,topic_changed)VALUES(?, ?, ?)'][参数:('Test2', '2018-09-03 05:21:08.730562', '2018-09-03 05:21:08.730562')] (此错误的背景:http://sqlalche.me/e/gkpj)
(sqlite3.IntegrityError)UNIQUE constraint failed:tab。tab_link[SQL:'INSERT INTO tab(tab_name,tab_link,tab_favicon,tab_description,tab_created,tab_changed,topic_id)VALUES(?, ?, ?, ?, ?, ?, ?)'][参数:('t1','t1l','t1f','t1d', '2018-09-03 05:21:08.733561', '2018-09-03 05:21:08.733561', 无)](此错误的背景在:http://sqlalche.me/e/gkpj)