当我尝试将if_exists='replace'参数传递给to_sql时，我收到编程错误，告诉我该表已存在：
>>> foobar.to_sql('foobar', engine, if_exists=u'replace')
...
ProgrammingError: (ProgrammingError) ('42S01', "[42S01] [Microsoft][ODBC SQL Server Driver][SQL Server]There is already an object named 'foobar' in the database. (2714) (SQLExecDirectW)") u'\nCREATE TABLE foobar...
从文档中听起来这个选项应该删除表并重新创建它，这不是观察到的行为。如果表已经不存在，则工作正常。如果这是一个错误或我做错了什么想法？
我使用pandas 0.14和sqlalchemy 0.8.3以及enthought canopy python发行版，并且我正在连接到SQL Server。
修改 根据joris＆＃39;注释：
>>>pd.__version__
Out[4]: '0.14.0'
>>>pd.io.sql.has_table('foobar', engine)
Out[7]: False
>>>foobar.to_sql('foobar', engine, if_exists=u'replace', index=False)
---------------------------------------------------------------------------
ProgrammingError Traceback (most recent call last)
<ipython-input-9-2f4ac7ed7f23> in <module>()
----> 1 foobar.to_sql('foobar', engine, if_exists=u'replace', index=False)
C:\Users\AppData\Local\Enthought\Canopy\User\lib\site-packages\pandas\core\generic.pyc in to_sql(self, name, con, flavor, if_exists, index, index_label)
948 sql.to_sql(
949 self, name, con, flavor=flavor, if_exists=if_exists, index=index,
--> 950 index_label=index_label)
951
952 def to_pickle(self, path):
C:\Users\AppData\Local\Enthought\Canopy\User\lib\site-packages\pandas\io\sql.pyc in to_sql(frame, name, con, flavor, if_exists, index, index_label)
438
439 pandas_sql.to_sql(frame, name, if_exists=if_exists, index=index,
--> 440 index_label=index_label)
441
442
C:\Users\AppData\Local\Enthought\Canopy\User\lib\site-packages\pandas\io\sql.pyc in to_sql(self, frame, name, if_exists, index, index_label)
812 table = PandasSQLTable(
813 name, self, frame=frame, index=index, if_exists=if_exists,
--> 814 index_label=index_label)
815 table.insert()
816
C:\Users\AppData\Local\Enthought\Canopy\User\lib\site-packages\pandas\io\sql.pyc in __init__(self, name, pandas_sql_engine, frame, index, if_exists, prefix, index_label)
530 else:
531 self.table = self._create_table_statement()
--> 532 self.create()
533 else:
534 # no data provided, read-only mode
C:\Users\AppData\Local\Enthought\Canopy\User\lib\site-packages\pandas\io\sql.pyc in create(self)
546
547 def create(self):
--> 548 self.table.create()
549
550 def insert_statement(self):
C:\Users\AppData\Local\Enthought\Canopy\User\lib\site-packages\sqlalchemy\schema.pyc in create(self, bind, checkfirst)
614 bind._run_visitor(ddl.SchemaGenerator,
615 self,
--> 616 checkfirst=checkfirst)
617
618 def drop(self, bind=None, checkfirst=False):
C:\Users\AppData\Local\Enthought\Canopy\User\lib\site-packages\sqlalchemy\engine\base.pyc in _run_visitor(self, visitorcallable, element, connection, **kwargs)
1477 connection=None, **kwargs):
1478 with self._optional_conn_ctx_manager(connection) as conn:
-> 1479 conn._run_visitor(visitorcallable, element, **kwargs)
1480
1481 class _trans_ctx(object):
C:\Users\AppData\Local\Enthought\Canopy\User\lib\site-packages\sqlalchemy\engine\base.pyc in _run_visitor(self, visitorcallable, element, **kwargs)
1120 def _run_visitor(self, visitorcallable, element, **kwargs):
1121 visitorcallable(self.dialect, self,
-> 1122 **kwargs).traverse_single(element)
1123
1124
C:\Users\AppData\Local\Enthought\Canopy\User\lib\site-packages\sqlalchemy\sql\visitors.pyc in traverse_single(self, obj, **kw)
120 meth = getattr(v, "visit_%s" % obj.__visit_name__, None)
121 if meth:
--> 122 return meth(obj, **kw)
123
124 def iterate(self, obj):
C:\Users\AppData\Local\Enthought\Canopy\User\lib\site-packages\sqlalchemy\engine\ddl.pyc in visit_table(self, table, create_ok)
87 self.traverse_single(column.default)
88
---> 89 self.connection.execute(schema.CreateTable(table))
90
91 if hasattr(table, 'indexes'):
C:\Users\AppData\Local\Enthought\Canopy\User\lib\site-packages\sqlalchemy\engine\base.pyc in execute(self, object, *multiparams, **params)
660 object,
661 multiparams,
--> 662 params)
663 else:
664 raise exc.InvalidRequestError(
C:\Users\AppData\Local\Enthought\Canopy\User\lib\site-packages\sqlalchemy\engine\base.pyc in _execute_ddl(self, ddl, multiparams, params)
718 compiled,
719 None,
--> 720 compiled
721 )
722 if self._has_events:
C:\Users\AppData\Local\Enthought\Canopy\User\lib\site-packages\sqlalchemy\engine\base.pyc in _execute_context(self, dialect, constructor, statement, parameters, *args)
872 parameters,
873 cursor,
--> 874 context)
875
876 if self._has_events:
C:\Users\AppData\Local\Enthought\Canopy\User\lib\site-packages\sqlalchemy\engine\base.pyc in _handle_dbapi_exception(self, e, statement, parameters, cursor, context)
1022 self.dialect.dbapi.Error,
1023 connection_invalidated=self._is_disconnect),
-> 1024 exc_info
1025 )
1026
C:\Users\AppData\Local\Enthought\Canopy\User\lib\site-packages\sqlalchemy\util\compat.pyc in raise_from_cause(exception, exc_info)
194 # the code line where the issue occurred
195 exc_type, exc_value, exc_tb = exc_info
--> 196 reraise(type(exception), exception, tb=exc_tb)
197
198
C:\Users\AppData\Local\Enthought\Canopy\User\lib\site-packages\sqlalchemy\engine\base.pyc in _execute_context(self, dialect, constructor, statement, parameters, *args)
865 statement,
866 parameters,
--> 867 context)
868 except Exception, e:
869 self._handle_dbapi_exception(
C:\Users\AppData\Local\Enthought\Canopy\User\lib\site-packages\sqlalchemy\engine\default.pyc in do_execute(self, cursor, statement, parameters, context)
322
323 def do_execute(self, cursor, statement, parameters, context=None):
--> 324 cursor.execute(statement, parameters)
325
326 def do_execute_no_params(self, cursor, statement, context=None):
ProgrammingError: (ProgrammingError) ('42S01', "[42S01] [Microsoft][ODBC SQL Server Driver][SQL Server]There is already an object named 'foobar' in the database. (2714) (SQLExecDirectW)") u'\nCREATE TABLE foobar (\n\tfactor TEXT NULL, \n\tnum_avail INTEGER NULL, \n\tpct_avail FLOAT NULL, \n\tmin FLOAT NULL, \n\tmax FLOAT NULL, \n\tptile1 FLOAT NULL, \n\tptile99 FLOAT NULL, \n\tpct_yday FLOAT NULL, \n\tdiff_yday FLOAT NULL, \n\tcorr_yday FLOAT NULL\n)\n\n' ()