在 SQL Alchemy 中更新布尔值（使用 CRUD）

Question

我正在尝试将布尔语句从默认值 False 更新为 True。这里的想法是用户观看了一些视频并且更新方法从 False 更改为 True。

我正在努力编写 update_view_state 方法。我已经尝试过点符号（我承认我是新手）但没有成功。

使用 Python 2.7 SQLALCHEMY 和 CRUD method

class View_State(Base):
    __tablename__ = 'view_states'
    #more code
    completed = Column(Boolean, default=False) #have to set default

    def __init__(self, user, video):
        self.completed = False

更新代码：

def update_view_state(self, username, videoname, completed):
    #update Boolean completed status to 'complete = True'
    update_view = self.session.query(View_State).\
    filter(View_State.user.has(username == username)).\
    filter(View_State.video.has(videoname == videoname)).one()
    if update_view:
        print 'update view found: ', update_view.completed
        update_view.completed.append(completed)
        self.session.commit()
        return update_view

Test.py

api.update_view_state('ack', 'module1', True)

回溯：

Traceback (most recent call last):
  File "/usr/local/lib/python2.7/site-packages/nose/case.py", line 197, in runTest
    self.test(*self.arg)
  File "/Users/ack/code/enotss_copy/NotssDB/notssdb/test/test.py", line 296, in test_crud_operations
    api.update_view_state('ack', 'module1', True)
  File "/Users/ack/code/enotss_copy/NotssDB/notssdb/api/convenience.py", line 35, in update_view_state
    return super(ConvenienceAPI, self).update_view_state(user, video, completed)
  File "/Users/ack/code/enotss_copy/NotssDB/notssdb/api/object.py", line 634, in update_view_state
    filter(View_State.user.has(username == username)).\
  File "/usr/local/lib/python2.7/site-packages/sqlalchemy/orm/interfaces.py", line 442, in has
    return self.operate(PropComparator.has_op, criterion, **kwargs)
  File "/usr/local/lib/python2.7/site-packages/sqlalchemy/orm/attributes.py", line 175, in operate
    return op(self.comparator, *other, **kwargs)
  File "/usr/local/lib/python2.7/site-packages/sqlalchemy/orm/interfaces.py", line 383, in has_op
    return a.has(b, **kwargs)
  File "/usr/local/lib/python2.7/site-packages/sqlalchemy/orm/relationships.py", line 1172, in has
    return self._criterion_exists(criterion, **kwargs)
  File "/usr/local/lib/python2.7/site-packages/sqlalchemy/orm/relationships.py", line 1081, in _criterion_exists
    criterion = criterion._annotate(
AttributeError: 'bool' object has no attribute '_annotate'

下面的答案：

回溯：

ERROR: notssdb.test.test.test_crud_operations
----------------------------------------------------------------------
Traceback (most recent call last):
  File "/usr/local/lib/python2.7/site-packages/nose/case.py", line 197, in runTest
    self.test(*self.arg)
  File "/Users/ack/code/enotss_copy/NotssDB/notssdb/test/test.py", line 295, in test_crud_operations
    api.update_view_state('ack', 'module1', True)
  File "/Users/ack/code/enotss_copy/NotssDB/notssdb/api/object.py", line 628, in update_view_state
    filter(View_State.user.has(username == username)).\
  File "/usr/local/lib/python2.7/site-packages/sqlalchemy/orm/interfaces.py", line 442, in has
    return self.operate(PropComparator.has_op, criterion, **kwargs)
  File "/usr/local/lib/python2.7/site-packages/sqlalchemy/orm/attributes.py", line 175, in operate
    return op(self.comparator, *other, **kwargs)
  File "/usr/local/lib/python2.7/site-packages/sqlalchemy/orm/interfaces.py", line 383, in has_op
    return a.has(b, **kwargs)
  File "/usr/local/lib/python2.7/site-packages/sqlalchemy/orm/relationships.py", line 1172, in has
    return self._criterion_exists(criterion, **kwargs)
  File "/usr/local/lib/python2.7/site-packages/sqlalchemy/orm/relationships.py", line 1081, in _criterion_exists
    criterion = criterion._annotate(
AttributeError: 'bool' object has no attribute '_annotate'

Answer 1

针对您的评论，我认为我最好 post 提供详细信息的答案。希望这可以帮助您清理它并正确运行。

def update_view_state(self, username, videoname, completed):
    #update Boolean completed status to 'complete = True'
    update_view = self.session.query(View_State).\
    filter(View_State.user.has(username == username)).\
    filter(View_State.video.has(videoname == videoname)).one()
    if update_view:
        print 'update view found: ', update_view.completed
        update_view.completed = True # Simply reassign it like a variable
        self.session.add(update_view) # Add it to the session
        self.session.commit() # And commit
        return update_view

我在代码中使用了 self.session，因为您正在使用它。我从来没有以这种方式设置我的会话，所以我只使用过 session.commit() 或 session.add()，但我试图与你所获得的 posted 保持一致，因为您的代码的其他一些未posted 部分可能需要这样做。

我在这里直接更新了布尔值 True，但我看到您已经采用了您可能更喜欢使用的函数参数 completed。在这种情况下，只需使用 update_view.completed = completed。也许考虑重命名该参数以避免与数据库中同名的列混淆。

如您所问，如果我们将参数 completed 重命名为 status_change，它将如下所示：

def update_view_state(self, username, videoname, status_change):
    #update Boolean completed status to 'complete = True'
    update_view = self.session.query(View_State).\
    filter(View_State.user.has(username == username)).\
    filter(View_State.video.has(videoname == videoname)).one()
    if update_view:
        print 'update view found: ', update_view.completed
        update_view.completed = status_change # Simply reassign it like a variable
        self.session.add(update_view) # Add it to the session
        self.session.commit() # And commit
        return update_view

在这种情况下，如果您想来回切换，可以使用函数将 update_view.completed 设置为 True 或 False。这样做只是将您选择的布尔值作为参数传递给函数。如果您只想使用此函数将其设置为 True，则可以完全删除 status_change 参数，并使用第一个示例中的原始布尔值。

在 SQL Alchemy 中更新布尔值（使用 CRUD）

Update boolean in SQL Alchemy (using CRUD)

boolean

sqlalchemy

crud

traceback

python-2.7