Question

我想使用pandas函数to_sql将数据帧写入MariaDB数据库。我在PyCharm中的Python代码如下所示：

import pandas as pd
import mysql.connector
from sqlalchemy import create_engine

myd = pd.read_csv('/[path]/[filename].csv')

engine = create_engine('mysql+mysqlconnector://[user]:[pw]@127.0.0.1/[dbname]')

myd.to_sql(name='[tablename]', con=engine, if_exists='replace', index=False)

在控制台中执行最后一行时，我收到以下错误：

Error on sql SELECT name FROM sqlite_master WHERE type='table' AND name='[tablename]'; 
Traceback (most recent call last):   
   File "/usr/lib/python3.4/code.py", line 90, in runcode
     exec(code, self.locals)   
   File "<input>", line 1, in <module>   
   File "/usr/lib/python3/dist-packages/pandas/core/frame.py", line 1261, in to_sql
     self, name, con, flavor=flavor, if_exists=if_exists, **kwargs)   
   File "/usr/lib/python3/dist-packages/pandas/io/sql.py", line 207, in write_frame
     exists = table_exists(name, con, flavor)   
   File "/usr/lib/python3/dist-packages/pandas/io/sql.py", line 275, in table_exists
     return len(tquery(query, con)) > 0   
   File "/usr/lib/python3/dist-packages/pandas/io/sql.py", line 90, in tquery
     cur = execute(sql, con, cur=cur)   
   File "/usr/lib/python3/dist-packages/pandas/io/sql.py", line 44, in execute
     cur = con.cursor() 
AttributeError: 'Engine' object has no attribute 'cursor'

Here有人在某一点上有同样的错误。然而，在有人解决问题之前，它已经消失了。你知道出了什么问题吗？

Answer 1

仅从pandas 0.14.0

开始支持传递sqlalchemy引擎

要将to_sql与较旧的pandas版本一起使用，您需要将原始连接（engine.raw_connection()）和flavor='mysql'传递给to_sql：

myd.to_sql(name='[tablename]', con=engine.raw_connection(), flavor='mysql', if_exists='replace', index=False)

但是，我建议升级你的pandas版本（不推荐使用原始连接，在新的pandas版本中不再支持，那么只支持sqlalchemy引擎/连接）

使用to_sql和sqlalchemy将pandas数据帧添加到mariadb数据库

1 个答案: