如何在Flask-SQLAlchemy中按ID删除记录-Python 实用宝典

如何在Flask-SQLAlchemy中按ID删除记录

我users在MySql数据库中有表。这个表有id,name而且age领域。 如何删除某些记录id? 现在,我使用以下代码: user = User.query.get(id) db.session.delete(user) db.session.commit() 但是我不想在删除操作之前进行任何查询。有什么办法吗?我知道,我可以使用db.engine.execute("delete from users where id=..."),但是我想使用delete()方法。

问题:如何在Flask-SQLAlchemy中按ID删除记录

users在MySql数据库中有表。这个表有idname而且age领域。

如何删除某些记录id

现在,我使用以下代码:

user = User.query.get(id)
db.session.delete(user)
db.session.commit()

但是我不想在删除操作之前进行任何查询。有什么办法吗?我知道,我可以使用db.engine.execute("delete from users where id=..."),但是我想使用delete()方法。

I have users table in my MySql database. This table has id, name and age fields.

How can I delete some record by id?

Now I use the following code:

user = User.query.get(id)
db.session.delete(user)
db.session.commit()

But I don't want to make any query before delete operation. Is there any way to do this? I know, I can use db.engine.execute("delete from users where id=..."), but I would like to use delete() method.


回答 0

你可以这样做,

User.query.filter_by(id=123).delete()

要么

User.query.filter(User.id == 123).delete()

确保作出commitdelete()生效。

You can do this,

User.query.filter_by(id=123).delete()

or

User.query.filter(User.id == 123).delete()

Make sure to commit for delete() to take effect.


回答 1

只想分享另一个选择:

# mark two objects to be deleted
session.delete(obj1)
session.delete(obj2)

# commit (or flush)
session.commit()

http://docs.sqlalchemy.org/en/latest/orm/session_basics.html#deleting

在此示例中,以下代码可以正常工作:

obj = User.query.filter_by(id=123).one()
session.delete(obj)
session.commit()

Just want to share another option:

# mark two objects to be deleted
session.delete(obj1)
session.delete(obj2)

# commit (or flush)
session.commit()

http://docs.sqlalchemy.org/en/latest/orm/session_basics.html#deleting

In this example, the following codes shall works fine:

obj = User.query.filter_by(id=123).one()
session.delete(obj)
session.commit()

回答 2

另一个可能的解决方案,特别是如果要批量删除

deleted_objects = User.__table__.delete().where(User.id.in_([1, 2, 3]))
session.execute(deleted_objects)
session.commit()

Another possible solution specially if you want batch delete

deleted_objects = User.__table__.delete().where(User.id.in_([1, 2, 3]))
session.execute(deleted_objects)
session.commit()

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