How to update SQLAlchemy row entry?

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Chapters
00:00 Question
00:48 Accepted answer (Score 190)
00:58 Answer 2 (Score 513)
01:26 Answer 3 (Score 59)
03:30 Answer 4 (Score 7)
04:01 Thank you

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Full question
https://stackoverflow.com/questions/9667...

Answer 3 links:
[SQLAlchemy: What's the difference between flush() and commit()?]: https://stackoverflow.com/questions/4201...

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Tags
#python #sqlalchemy #flasksqlalchemy

#avk47

ANSWER 1

Score 561

There are several ways to UPDATE using SQLAlchemy:

user.no_of_logins += 1
session.commit()

session.query(User).\
    filter(User.username == form.username.data).\
    update({'no_of_logins': User.no_of_logins + 1})
session.commit()

conn = engine.connect()
stmt = User.update().\
    values(no_of_logins=User.no_of_logins + 1).\
    where(User.username == form.username.data)
conn.execute(stmt)

setattr(user, 'no_of_logins', user.no_of_logins + 1)
session.commit()

ACCEPTED ANSWER

Score 206

user.no_of_logins += 1
session.commit()

ANSWER 3

Score 8

I wrote telegram bot, and have some problem with update rows. Use this example, if you have Model

def update_state(chat_id, state):
    try:
        value = Users.query.filter(Users.chat_id == str(chat_id)).first()
        value.state = str(state)
        db.session.flush()
        db.session.commit()
        #db.session.close()
    except:
        print('Error in def update_state')

Why use db.session.flush()? That's why >>> SQLAlchemy: What's the difference between flush() and commit()?

ANSWER 4

Score 6

With the help of user=User.query.filter_by(username=form.username.data).first() statement you will get the specified user in user variable.

Now you can change the value of the new object variable like user.no_of_logins += 1 and save the changes with the session's commit method.