How to update data of one column for all rows in SqlAlchemy?

2021 Answer

As of sqlalchemy==1.4 and the upcoming release of 2.0, the recommended way of performing an UPDATE is via the SA-builtin update function, rather than the .update method.

Example:

from sqlalchemy import update

uid=1

# MY_CONDITION is whatever condition triggers the change in status value
update(Uninstall).where(MY_CONDITION).values(status=uid)

If you want to change the status value to be equal to uid for all columns, then you can simply do it unconditionally:

update(Uninstall).values(status=uid)

Finally, don't forget to commit:

session.commit()

Source: https://docs.sqlalchemy.org/en/14/core/dml.html?highlight=update#sqlalchemy.sql.expression.update

The suggested is not optimized. You can use the options to update: 1.

for row in Uninstall.query:  # all() is extra
    row.status = new_status
Session.commit()

If there are lots of rows, it can be faster, but it will invoke UPDATE for every row. Not good, is it?

2.

Uninstall.query.update({Uninstall.status: new_status}) 
Session.commit()

Invokes only one UPDATE query for all rows.