所以我尝试了几个不同的东西。这是什么不工作，什么最终没有工作：

没有工作：

pre > ＃这将抛出一个异常，AttributeError：任务'对象没有任何属性'更新'
db.session.query（Task）.get（id）.update（{状态：状态}）
db.session.commit（）

＃这是链接的SO线程中的示例：
＃不做任何事
db.session .query（Task）.filter_by（id = id）.update（{state：state}）

#this也没有做任何事
task = Task.query.filter_by（id = id）
task.state = state
db.session.commit（）

＃不是
task = Task.query.get（id）
task.state = state
db.session.commit（）


  #ok这样做：
 db.session.query（Task）.filter_by（id = id）.update （{state：state}）
 db.session.commit（）

＃也是这样的：
 task = db.session.query（Task）.get id）
 task.state =状态
 db.session.commit（）
 

I followed the (two) examples in this question: SQLAlchemy: a better way for update with declarative?

And I'm finding that a model update does not happen when using sqlite with flask-sqlalchemy on Ubuntu Linux. The very simplest example doesn't work for me:

class Task:
    id= db.Column(db.Integer, primary_key=True)
    name= db.Column(db.String(32), unique=True)
    desc= db.Column(db.String(255), unique=False)
    state= db.Column(db.Boolean)

    # ...

@app.route("/task/<int:id>/update",methods=["POST"])
def toggle_state(id):
    db.session.query(Task).get(id).update({"state":True})
    log.info("state is now: " + str(Task.query.get(id).state))
    # prints "state is now: False"

First time using flask/sqlalchemy, so I assume I'm missing something obvious.

So I tried several different things. Here's what didn't work, and what finally did work:

Didn't work:

# this will throw an exception, "AttributeError: 'Task' object has no attribute 'update'"
db.session.query(Task).get(id).update({"state":state})
db.session.commit()

# this was the example in the linked SO thread:
# does nothing
db.session.query(Task).filter_by(id=id).update({"state":state})

#this also does nothing
task = Task.query.filter_by(id=id)
task.state = state
db.session.commit()

#not this either
task = Task.query.get(id)
task.state = state
db.session.commit()

Did work:

#ok this works:
db.session.query(Task).filter_by(id=id).update({"state":state})
db.session.commit()

#and also this:
task = db.session.query(Task).get(id)
task.state = state
db.session.commit()