Python 鏈接數據庫失敗

什麼是 PyMySQL？

PyMySQL 是在 Python3.x 版本中用於鏈接 MySQL 服務器的一個庫，Python2中則使用mysqldb。

PyMySQL 遵循 Python 數據庫 API v2.0 規範，幷包含了 pure-Python MySQL 客戶端庫。

在使用 PyMySQL 以前，咱們須要確保 PyMySQL 已安裝。

PyMySQL 下載地址：https://github.com/PyMySQL/PyMySQL。

若是還未安裝，咱們能夠使用如下命令安裝最新版的 PyMySQL：

$ pip3 install PyMySQL

如下實例連接 Mysql 的 TESTDB 數據庫：

#!/usr/bin/python3
 
import pymysql
 
# 打開數據庫鏈接
db = pymysql.connect("localhost","testuser","test123","TESTDB" )
 
# 使用 cursor() 方法建立一個遊標對象 cursor
cursor = db.cursor()
 
# 使用 execute()  方法執行 SQL 查詢 
cursor.execute("SELECT VERSION()")
 
# 使用 fetchone() 方法獲取單條數據.
data = cursor.fetchone()
 
print ("Database version : %s " % data)
 
# 關閉數據庫鏈接
db.close()

報錯以下：

 

Traceback (most recent call last):
File "/Library/Frameworks/Python.framework/Versions/3.7/lib/python3.7/site-packages/pymysql/connections.py", line 582, in connect
**kwargs)
File "/Library/Frameworks/Python.framework/Versions/3.7/lib/python3.7/socket.py", line 727, in create_connection
raise err
File "/Library/Frameworks/Python.framework/Versions/3.7/lib/python3.7/socket.py", line 716, in create_connection
sock.connect(sa)
ConnectionRefusedError: [Errno 61] Connection refused

 

During handling of the above exception, another exception occurred:

 

Traceback (most recent call last):
File "mysql_conn.py", line 6, in <module>
db = pymysql.connect("localhost","root","201995zjh","ryan" )
File "/Library/Frameworks/Python.framework/Versions/3.7/lib/python3.7/site-packages/pymysql/__init__.py", line 94, in Connect
return Connection(*args, **kwargs)
File "/Library/Frameworks/Python.framework/Versions/3.7/lib/python3.7/site-packages/pymysql/connections.py", line 327, in __init__
self.connect()
File "/Library/Frameworks/Python.framework/Versions/3.7/lib/python3.7/site-packages/pymysql/connections.py", line 629, in connect
raise exc
pymysql.err.OperationalError: (2003, "Can't connect to MySQL server on 'localhost' ([Errno 61] Connection refused)")

 

 

在肯定安裝了 PyMySQL 以及數據庫帳號密碼等沒有問題時，仍是不能鏈接 MySQL，

最後只剩下兩種可能：

1. 運行 mysqladmin variables | grep socket 來獲取套接字所在的位置，並嘗試設置以下鏈接：

pymysql.connect(db='base', user='root', passwd='pwd', unix_socket="/tmp/mysql.sock")

 

2. 運行 mysqladmin variables | grep port 並驗證端口是3306.若是沒有，您能夠手動設置端口，以下所示：

pymysql.connect(db='base', user='root', passwd='pwd', host='localhost', port=XXXX)

 

https://stackoverflow.com/questions/6885164/pymysql-cant-connect-to-mysql-on-localhost