python - 左连接的 SQLAlchemy 错误

Question

我是 SQLAlchemy 的新手，我正在尝试实现这个 SQL:

SELECT 
    node.*,
    alarms.*
FROM
    node
        LEFT JOIN
            alarms ON alarms.nodeid = node.nodeid 
WHERE
    node.foreignid IN ('foreignid_1','foreignid_2','foreignid_3') 
ORDER BY node.nodeid;

我想出了这个声明:

stmt = session.query(Node, Alarms).outerjoin(Alarms, Alarms.nodeid == Node.nodeid).filter(Node.foreignid.in_(['foreignid_1','foreignid_2','foreignid_3'])).order_by(asc(Node.nodeid))
results = stmt.all()

生成的 SQL 如下所示:

SELECT 
    node.nodeid AS node_nodeid,
    node.dpname AS node_dpname,
    node.nodecreatetime AS node_nodecreatetime,
    node.nodeparentid AS node_nodeparentid,
    node.nodetype AS node_nodetype,
    node.nodesysoid AS node_nodesysoid,
    node.nodesysname AS node_nodesysname,
    node.nodesysdescription AS node_nodesysdescription,
    node.nodesyslocation AS node_nodesyslocation,
    node.nodesyscontact AS node_nodesyscontact,
    node.nodelabel AS node_nodelabel,
    node.nodelabelsource AS node_nodelabelsource,
    node.nodenetbiosname AS node_nodenetbiosname,
    node.nodedomainname AS node_nodedomainname,
    node.operatingsystem AS node_operatingsystem,
    node.lastcapsdpoll AS node_lastcapsdpoll,
    node.foreignsource AS node_foreignsource,
    node.foreignid AS node_foreignid,
    alarms.alarmid AS alarms_alarmid,
    alarms.eventuei AS alarms_eventuei,
    alarms.dpname AS alarms_dpname,
    alarms.nodeid AS alarms_nodeid,
    alarms.ipaddr AS alarms_ipaddr,
    alarms.serviceid AS alarms_serviceid,
    alarms.reductionkey AS alarms_reductionkey,
    alarms.alarmtype AS alarms_alarmtype,
    alarms.counter AS alarms_counter,
    alarms.severity AS alarms_severity,
    alarms.lasteventid AS alarms_lasteventid,
    alarms.firsteventtime AS alarms_firsteventtime,
    alarms.lasteventtime AS alarms_lasteventtime,
    alarms.firstautomationtime AS alarms_firstautomationtime,
    alarms.lastautomationtime AS alarms_lastautomationtime,
    alarms.description AS alarms_description,
    alarms.logmsg AS alarms_logmsg,
    alarms.operinstruct AS alarms_operinstruct,
    alarms.tticketid AS alarms_tticketid,
    alarms.tticketstate AS alarms_tticketstate,
    alarms.mouseovertext AS alarms_mouseovertext,
    alarms.suppresseduntil AS alarms_suppresseduntil,
    alarms.suppresseduser AS alarms_suppresseduser,
    alarms.suppressedtime AS alarms_suppressedtime,
    alarms.alarmackuser AS alarms_alarmackuser,
    alarms.alarmacktime AS alarms_alarmacktime,
    alarms.managedobjectinstance AS alarms_managedobjectinstance,
    alarms.managedobjecttype AS alarms_managedobjecttype,
    alarms.applicationdn AS alarms_applicationdn,
    alarms.ossprimarykey AS alarms_ossprimarykey,
    alarms.x733alarmtype AS alarms_x733alarmtype,
    alarms.x733probablecause AS alarms_x733probablecause,
    alarms.qosalarmstate AS alarms_qosalarmstate,
    alarms.clearkey AS alarms_clearkey,
    alarms.ifindex AS alarms_ifindex,
    alarms.eventparms AS alarms_eventparms
FROM
    node
        LEFT OUTER JOIN
            alarms ON alarms.nodeid = node.nodeid
WHERE
    node.foreignid IN ('foreignid_2' , 'foreignid_1', 'foreignid_3')
ORDER BY node.nodeid ASC  

但它也会抛出这个错误(来自 iPython):

In [86]: stmt = session.query(Node, Alarms).outerjoin(Alarms, Alarms.nodeid == Node.nodeid).filter(Node.foreignid.in_(['foreignid_1','foreignid_3','foreignid_2'])).order_by(asc(Node.nodeid))

In [87]: results = stmt.all()
---------------------------------------------------------------------------
InternalError                             Traceback (most recent call last)
<ipython-input-87-1110c354b407> in <module>()
----> 1 results = stmt.all()

/usr/local/lib/python2.6/dist-packages/SQLAlchemy-0.7.8-py2.6-linux-x86_64.egg/sqlalchemy/orm/query.pyc in all(self)
   2113
   2114         """
-> 2115         return list(self)
   2116
   2117     @_generative(_no_clauseelement_condition)

/usr/local/lib/python2.6/dist-packages/SQLAlchemy-0.7.8-py2.6-linux-x86_64.egg/sqlalchemy/orm/query.pyc in __iter__(self)
   2225         if self._autoflush and not self._populate_existing:
   2226             self.session._autoflush()
-> 2227         return self._execute_and_instances(context)
   2228
   2229     def _connection_from_session(self, **kw):

/usr/local/lib/python2.6/dist-packages/SQLAlchemy-0.7.8-py2.6-linux-x86_64.egg/sqlalchemy/orm/query.pyc in _execute_and_instances(self, querycontext)
   2240                         close_with_result=True)
   2241
-> 2242         result = conn.execute(querycontext.statement, self._params)
   2243         return self.instances(result, querycontext)
   2244

/usr/local/lib/python2.6/dist-packages/SQLAlchemy-0.7.8-py2.6-linux-x86_64.egg/sqlalchemy/engine/base.pyc in execute(self, object, *multiparams, **params)
   1447                                                 object,
   1448                                                 multiparams,
-> 1449                                                 params)
   1450         else:
   1451             raise exc.InvalidRequestError(

/usr/local/lib/python2.6/dist-packages/SQLAlchemy-0.7.8-py2.6-linux-x86_64.egg/sqlalchemy/engine/base.pyc in _execute_clauseelement(self, elem, multiparams, params)
   1582             compiled_sql,
   1583             distilled_params,
-> 1584             compiled_sql, distilled_params
   1585         )
   1586         if self._has_events:

/usr/local/lib/python2.6/dist-packages/SQLAlchemy-0.7.8-py2.6-linux-x86_64.egg/sqlalchemy/engine/base.pyc in _execute_context(self, dialect, constructor, statement, parameters, *args)
   1696                                 parameters,
   1697                                 cursor,
-> 1698                                 context)
   1699             raise
   1700

/usr/local/lib/python2.6/dist-packages/SQLAlchemy-0.7.8-py2.6-linux-x86_64.egg/sqlalchemy/engine/base.pyc in _execute_context(self, dialect, constructor, statement, parameters, *args)
   1689                                     statement,
   1690                                     parameters,
-> 1691                                     context)
   1692         except Exception, e:
   1693             self._handle_dbapi_exception(

/usr/local/lib/python2.6/dist-packages/SQLAlchemy-0.7.8-py2.6-linux-x86_64.egg/sqlalchemy/engine/default.pyc in do_execute(self, cursor, statement, parameters, context)
    329
    330     def do_execute(self, cursor, statement, parameters, context=None):
--> 331         cursor.execute(statement, parameters)
    332
    333     def do_execute_no_params(self, cursor, statement, context=None):

InternalError: (InternalError) current transaction is aborted, commands ignored until end of transaction block
 'SELECT node.nodeid AS node_nodeid, node.dpname AS node_dpname, node.nodecreatetime AS node_nodecreatetime, node.nodeparentid AS node_nodeparentid, node.nodetype AS node_nodetype, node.nodesysoid AS node_nodesysoid, node.nodesysname AS node_nodesysname, node.nodesysdescription AS node_nodesysdescription, node.nodesyslocation AS node_nodesyslocation, node.nodesyscontact AS node_nodesyscontact, node.nodelabel AS node_nodelabel, node.nodelabelsource AS node_nodelabelsource, node.nodenetbiosname AS node_nodenetbiosname, node.nodedomainname AS node_nodedomainname, node.operatingsystem AS node_operatingsystem, node.lastcapsdpoll AS node_lastcapsdpoll, node.foreignsource AS node_foreignsource, node.foreignid AS node_foreignid, alarms.alarmid AS alarms_alarmid, alarms.eventuei AS alarms_eventuei, alarms.dpname AS alarms_dpname, alarms.nodeid AS alarms_nodeid, alarms.ipaddr AS alarms_ipaddr, alarms.serviceid AS alarms_serviceid, alarms.reductionkey AS alarms_reductionkey, alarms.alarmtype AS alarms_alarmtype, alarms.counter AS alarms_counter, alarms.severity AS alarms_severity, alarms.lasteventid AS alarms_lasteventid, alarms.firsteventtime AS alarms_firsteventtime, alarms.lasteventtime AS alarms_lasteventtime, alarms.firstautomationtime AS alarms_firstautomationtime, alarms.lastautomationtime AS alarms_lastautomationtime, alarms.description AS alarms_description, alarms.logmsg AS alarms_logmsg, alarms.operinstruct AS alarms_operinstruct, alarms.tticketid AS alarms_tticketid, alarms.tticketstate AS alarms_tticketstate, alarms.mouseovertext AS alarms_mouseovertext, alarms.suppresseduntil AS alarms_suppresseduntil, alarms.suppresseduser AS alarms_suppresseduser, alarms.suppressedtime AS alarms_suppressedtime, alarms.alarmackuser AS alarms_alarmackuser, alarms.alarmacktime AS alarms_alarmacktime, alarms.managedobjectinstance AS alarms_managedobjectinstance, alarms.managedobjecttype AS alarms_managedobjecttype, alarms.applicationdn AS alarms_applicationdn, alarms.ossprimarykey AS alarms_ossprimarykey, alarms.x733alarmtype AS alarms_x733alarmtype, alarms.x733probablecause AS alarms_x733probablecause, alarms.qosalarmstate AS alarms_qosalarmstate, alarms.clearkey AS alarms_clearkey, alarms.ifindex AS alarms_ifindex, alarms.eventparms AS alarms_eventparms \nFROM node LEFT OUTER JOIN alarms ON alarms.nodeid = node.nodeid \nWHERE node.foreignid IN (%(foreignid_1)s, %(foreignid_2)s, %(foreignid_3)s) ORDER BY node.nodeid ASC' {'foreignid_1': 'foreignid_1', 'foreignid_3': 'foreignid_3', 'foreignid_2': 'foreignid_2'}

生成的 SQL 很好，我只是不明白错误是什么。

谢谢。

Answer 1

您的异常与您生成的 SQL 无关，这正是您想要的。

您的数据库连接处于错误状态；事务中止(可能是由于某处的完整性错误)并且没有启动新事务，并且您的数据库不喜欢这样。

在 iPython 提示符下试验 SQLAlchemy 时，最好打开自动提交，这样您就不必处理复杂的事务管理。