使用Python連結Oracle，利用cx_Oracle

Oracle client install這裡就不說明，可以google搜尋如何安裝。
Oracle tnsnames.ora 檔案範例，要注意的三個地方 Host Name/Port Number/Service Name，填入Python程式中。

SYSTEM_OCON =
(DESCRIPTION =
(ADDRESS = (PROTOCOL = TCP)(HOST = Host Name)(PORT = Port Number))
(LOAD_BALANCE = YES)
(CONNECT_DATA =
(SERVER = DEDICATED)
(SERVICE_NAME = Service Name)
(FAILOVER_MODE =
(TYPE = SELECT)
(METHOD = BASIC)
(RETRIES = 180)
(DELAY = 5)

Python 連結程式：

import cx_Oracle
import io
import sys
sys.stdout = io.TextIOWrapper(sys.stdout.buffer, encoding='utf8')

dsn_tns = cx_Oracle.makedsn('Host Name', 'Port Number', service_name='Service Name') 
conn = cx_Oracle.connect(user=r'User Name', password='Personal Password', dsn=dsn_tns)

c = conn.cursor()
c.execute('select * from database.table')
for row in c:
    print (row[0], '-', row[1])
conn.close()

程式參考
以上這一個連接語法可以成功。

底下使用方式，會一直出現錯誤無法連接Oracle資料庫。

connection = cx_Oracle.connect('使用者名稱/密碼@主機名稱/服務名稱',                                                encoding='UTF-8', nencoding='UTF-8') 

程式參考