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需要帮助来通过SQLALCHEMY连接到MySQL时发现问题。 下面是我的尝试:通过SQLALCHEMY连接到Mysql的Python连接
from sqlalchemy import create_engine
import pandas
def return_connection_string(database_name, database_user, database_password, database_host, database_port):
try:
connection_string = 'mysql+mysqlconnector://' + database_user + ':' + database_password + '@' + database_host + ':' + database_port + '/' + database_name
print(connection_string)
return connection_string
except Exception as e:
print('Encountered error while generating connection string for MySQL!')
print(e)
def return_connection_object(database_name, database_user, database_password, database_host, database_port):
try:
connection_string = return_connection_string(database_name, database_user, database_password, database_host, database_port)
engine = create_engine(connection_string).connect()
return engine
except Exception as e:
print('Encountered error while connecting to MySQL database!')
print(e)
mysql_conn = return_connection_object('db_name', 'db_user', 'db_pass', 'xyz.abc.com', '4100')
df = pandas.read_sql_query('select distinct table_name from information_schema.tables', mysql_conn)
print(df.shape)
mysql_conn.close()
以上脚本的工作完全正常,并返回所需的输出。 的问题是,当我尝试基于类的方法如下:
from sqlalchemy import create_engine
import logging
class Connection_class(object):
def __init__(self):
pass
def return_connection_string(self, database_name, database_user, database_password, database_host, database_port):
try:
connection_string = 'mysql+mysqlconnector://' + database_user + ':' + database_password + '@' + database_host + ':' + database_port + '/' + database_name
print(connection_string)
return connection_string
except Exception as e:
print('Encountered error while generating connection string for MySQL!')
print(e)
def return_connection_object(self, database_name, database_user, database_password, database_host, database_port):
try:
connection_string = self.return_connection_string(database_name, database_user, database_password, database_host, database_port)
engine = create_engine(connection_string).connect()
return engine
except Exception as e:
print('Encountered error while connecting to MySQL database!')
print(e)
我包上面的类在一个名为mysql软件包。该main.py是如下:
from mysql import connector
import pandas
mysql_obj = connector()
mysql_conn = mysql_obj.return_connection_object('db_name', 'db_user', 'db_pass', 'xyz.abc.com', '4100')
df = pandas.read_sql_query('select distinct table_name from information_schema.tables', mysql_conn)
mysql_conn.close()
我得到的错误是: 对象类型“Connection_class”有没有属性“paramstyle”
在调试,我发现从return_connection_object功能发起的错误,不知何故,当它作为脚本运行时,完全相同的函数返回连接对象时它返回null。
任何线索都会有帮助。提前致谢。