注意 – 正如下面提到的MaxU,问题是mysql.connector特有的,如果使用pyMysqL则不会发生.希望这可以为别人带来一些麻烦
使用Python,Pandas和MysqL并不能获得存储过程来返回结果,更不用说进入数据框了.
我一直收到有关多个查询的错误,但我运行的存储过程是非常简单的参数驱动查询.
无论我使用什么存储过程,它总是相同的结果
实际上,下面的测试程序(sp_test)是以下查询 –
select * from users;
如果我用同一个语句运行
df=pd.read_sql("select * from users", cnx,index_col=None, coerce_float=True)
代替
df=pd.read_sql("call sp_test()", cnx,index_col=None, coerce_float=True)
它工作正常,即使sp_test是来自用户的select *
为什么我一直收到multi = true错误消息,如何解决问题并获取存储过程的结果?我不明白一个简单的select语句将如何返回多个结果集.
如果有另一种方法可以做到这一点,很高兴尝试.
以下是我正在使用的简单代码
import pandas as pd
from pandas.io.data import DataReader
from pandas import DataFrame
import MysqL.connector
cnx = MysqL.connector.connect(user='jeff', password='password', database='testdatabase', host='xx.xxx.xxx.xx')
df=pd.read_sql("call sp_test()", cnx,index_col=None, coerce_float=True)
InterfaceError Traceback (most recent call last)
C:\Users\User\AppData\Local\Continuum\Anaconda3\lib\site- packages\MysqL\connector\cursor.py in execute(self, operation, params, multi)
506 try:
--> 507 self._handle_result(self._connection.cmd_query(stmt))
508 except errors.InterfaceError:
C:\Users\User\AppData\Local\Continuum\Anaconda3\lib\site-packages\MysqL\connector\connection.py in cmd_query(self, query)
725 raise errors.InterfaceError(
--> 726 'Use cmd_query_iter for statements with multiple queries.')
727
InterfaceError: Use cmd_query_iter for statements with multiple queries.
During handling of the above exception, another exception occurred:
InterfaceError Traceback (most recent call last)
C:\Users\User\AppData\Local\Continuum\Anaconda3\lib\site- packages\pandas\io\sql.py in execute(self, *args, **kwargs)
1563 else:
-> 1564 cur.execute(*args)
1565 return cur
C:\Users\User\AppData\Local\Continuum\Anaconda3\lib\site- packages\MysqL\connector\cursor.py in execute(self, operation, params, multi)
510 raise errors.InterfaceError(
--> 511 "Use multi=True when executing multiple statements")
512 raise
InterfaceError: Use multi=True when executing multiple statements
解决方法:
希望这会有所帮助.使用here中的一些概念指针和一点试验/错误,我能够使用MysqL.connector和pandas完成这项工作.
# CONNECT TO DB AND GET CURSOR OBJECT
conn = <do db connecty stuff>
cur = conn.cursor()
# CALL THE STORED PROCEDURE
cur.callproc('stored_proc_name', ['my', 'usp', 'parameters'])
# EXTRACT RESULTS FROM CURSOR
for i in cur.stored_results(): results = i.fetchall()
# LOAD INTO A DATAFRAME
df = pd.DataFrame(results, columns=['my', 'column', 'headers'])
这对我来说非常有用……我希望它也适合你.