使用SQLAlchemy，to_sql用 pandas 写入MySQL数据库 [英] Writing to MySQL database with pandas using SQLAlchemy, to_sql

问题描述

尝试使用to_sql将熊猫数据帧写入MySQL表.以前一直使用flavor='mysql'，但是将来会贬值，并希望开始过渡到使用SQLAlchemy引擎.

trying to write pandas dataframe to MySQL table using to_sql. Previously been using flavor='mysql', however it will be depreciated in the future and wanted to start the transition to using SQLAlchemy engine.

示例代码:

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

engine = create_engine('mysql+mysqlconnector://[user]:[pass]@[host]:[port]/[schema]', echo=False)
cnx = engine.raw_connection()
data = pd.read_sql('SELECT * FROM sample_table', cnx)
data.to_sql(name='sample_table2', con=cnx, if_exists = 'append', index=False)

读取正常，但to_sql出现错误:

The read works fine but the to_sql has an error:

DatabaseError:在SQL'SELECT name from sqlite_master中执行失败 WHERE type ='table'AND name = ?;':期间的参数数量错误 字符串格式

DatabaseError: Execution failed on sql 'SELECT name FROM sqlite_master WHERE type='table' AND name=?;': Wrong number of arguments during string formatting

为什么看起来要使用sqlite?将sqlalchemy连接与mysql特别是mysql.connector正确使用是什么?

Why does it look like it is trying to use sqlite? What is the correct use of a sqlalchemy connection with mysql and specifically mysql.connector?

我也尝试将引擎作为连接传递，这给了我一个错误，该错误引用了任何游标对象.

I also tried passing the engine in as the connection as well, and that gave me an error referencing no cursor object.

data.to_sql(name='sample_table2', con=engine, if_exists = 'append', index=False)
>>AttributeError: 'Engine' object has no attribute 'cursor'

推荐答案

使用引擎代替raw_connection()起作用:

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

engine = create_engine('mysql+mysqlconnector://[user]:[pass]@[host]:[port]/[schema]', echo=False)
data.to_sql(name='sample_table2', con=engine, if_exists = 'append', index=False)

不清楚为什么我昨天尝试此操作时会给我更早的错误.

Not clear on why when I tried this yesterday it gave me the earlier error.

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