python - How to delete a record by id in Flask-SQLAlchemy

Question

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.

Answer 1

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.

Answer 2

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()

Answer 3

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()

Answer 4

In sqlalchemy 1.4 (2.0 style) you can do it like this:

from sqlalchemy import select, update, delete, values

sql1 = delete(User).where(User.id.in_([1, 2, 3]))
sql2 = delete(User).where(User.id == 1)

db.session.execute(sql1)
db.session.commit()

or

u = db.session.get(User, 1)
db.session.delete(u)
db.session.commit()

In my opinion using select, update, delete is more readable. Style comparison 1.0 vs 2.0 can be found here