python - SQLAlchemy + Postgres + Python 完整性错误

Question

我有一个 python 应用程序，我相信它使用 postgres 9.1 和 sqlalchemy 0.7 在 2.7 版上运行。

我有一个 wx python gui，我可以从中添加和删除项目。代码工作正常但现在在进行一些修改后我收到了

$self.session.commit()
$  File "build\bdist.win32\egg\sqlalchemy\orm\session.py", line 645, in commit
$  File "build\bdist.win32\egg\sqlalchemy\orm\session.py", line 313, in commit
$  File "build\bdist.win32\egg\sqlalchemy\orm\session.py", line 297, in _prepare_impl
$  File "build\bdist.win32\egg\sqlalchemy\orm\session.py", line 1547, in flush
$  File "build\bdist.win32\egg\sqlalchemy\orm\session.py", line 1616, in _flush
$  File "build\bdist.win32\egg\sqlalchemy\orm\unitofwork.py", line 328, in execute
$  File "build\bdist.win32\egg\sqlalchemy\orm\unitofwork.py", line 472, in execute
$  File "build\bdist.win32\egg\sqlalchemy\orm\mapper.py", line 2291, in _save_obj
$  File "build\bdist.win32\egg\sqlalchemy\engine\base.py", line 1405, in execute
$ File "build\bdist.win32\egg\sqlalchemy\engine\base.py", line 1538, in           
$ _execute_clauseelement
$  File "build\bdist.win32\egg\sqlalchemy\engine\base.py", line 1646, in     
$_execute_context
$  File "build\bdist.win32\egg\sqlalchemy\engine\base.py", line 1639, in 
$_execute_context
$  File "build\bdist.win32\egg\sqlalchemy\engine\default.py", line 330, in do_execute
$sqlalchemy.exc.IntegrityError: (IntegrityError) duplicate key value violates
$ unique constraint "Equipment_pkey"
$DETAIL:  Key (id)=(4) already exists.
$ 'INSERT INTO "Equipment" (name, "numPorts") VALUES (%(name)s, %(numPorts)s)     
$RETURNING "HWCIs".id' {'numPorts': 0, 'name': u'jkhj'}

现在，当我重新启动应用程序时， key ID 增加了一个。我可以清楚地看到某些东西正在重置数据库的 ID 序列。任何人都可以帮助我如何通过编写 python 代码来解决这个问题，或者解决这个问题的简单步骤是什么。我尝试通过 psql 命令工作，但由于我缺乏知识而没有成功。如果可以通过简单的步骤解释解决方案，那就太好了。

Answer 1

好吧，我找到了答案。我正在连接到另一个数据库连接，这导致数据库序列重置为 1。因此，当应用程序启动时，它会寻找 position 1。所以我只需要将 sequence 更改为 last no。有效!