使用烧瓶炼金术在 SQLlite 中未设置外键约束 [英] Foreign key contraint is not getting set in SQLlite using flask alchemy

问题描述

我在 sqlalchemy 中定义了下表模式，其中 user_id 是引用用户的 user_id 表的外键

I have below table schema defined in sqlalchemy where user_id is foreign key referencing to User's user_id table

class Manufacturer(Model):
__tablename__='Manufacturer'
Manufacturer_id=Column(Integer,primary_key=True,autoincrement=True)
name=Column(String(length=100),nullable=False)
description=Column(String(length=1000),nullable=False)
user_id=Column(Integer,ForeignKey(User.user_id),nullable=False)

但是当在 sqllite db 中创建表时，外键未添加到表中，即使用户表没有 userid 值，也会插入条目

but when table is created in sqllite db foreign key not added to table and entry is getting inserted even though user table does not have value for userid

我搜索了这个问题，发现为了解决这个问题我们需要设置PRAGMA foreign_keys = ON;
但我无法弄清楚如何使用我当前的 DB 配置来完成

i searched for this issue and found in order to solve this problem we need to set PRAGMA foreign_keys = ON;
but i am not able to figure it out how this can be done with my current configuration for DB

我有以下代码来创建引擎并使用 SQL 添加记录引擎配置:-

i have below code to create engine and to add record with SQL Configuration for engine :-

engine=create_engine(SQLALCHEMY_DATABASE_URI)_Session=orm.sessionmaker(autocommit=False,autoflush=True,bind=engine)session=orm.scoped_session(_Session)

在表格中添加条目的代码

code to add entry in table

 man_details=Manufacturer(**param)
    session.add(man_details)
    session.commit()

请建议我如何从 python-Flask-SQLAlchemy 为在 SQLlite3 中创建的表设置外键约束

Please suggest how i can set foreign key constraint from python-Flask-SQLAlchemy for tables created in SQLlite3

推荐答案

下面的代码对我有用，并从下面的链接找到它 -

below code worked for me and found it from below link -

Sqlite/SQLAlchemy:如何强制使用外键?

   def _fk_pragma_on_connect(dbapi_con, con_record):
    dbapi_con.execute('pragma foreign_keys=ON')

from sqlalchemy import event
event.listen(engine, 'connect', _fk_pragma_on_connect)

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