oracle tnsnames.ora

http://www.aspphp.online/shujuku/oraclesjk/oraclezs/201701/226892.html

環境
db01  = 192.168.240.171  ver 11.2.0.4
db03 =  192.168.240.173  ver 19.3.0.0



--- Create User

CREATE USER  pythonhol  IDENTIFIED BY welcome   ;
-- SYSTEM PRIVILEGES
GRANT CREATE SESSION TO  pythonhol   ;
GRANT SELECT ANY DICTIONARY TO pythonhol    ;














---

Test Client


db1 =
  (DESCRIPTION =
    (ADDRESS = (PROTOCOL = TCP)(HOST = 192.168.240.171)(PORT = 1521))
    (CONNECT_DATA =
      (SERVER = DEDICATED)
      (SERVICE_NAME = orcl)
    )
  )

db3 =
  (DESCRIPTION =
    (ADDRESS = (PROTOCOL = TCP)(HOST = 192.168.240.173)(PORT = 1521))
    (CONNECT_DATA =
      (SERVER = DEDICATED)
      (SERVICE_NAME = orcl)
    )
  )

db =
  (DESCRIPTION =
    (LOAD_BALANCE=on)
    (FAILOVER=on)
    (ADDRESS = (PROTOCOL = TCP)(HOST = 192.168.240.171)(PORT = 1521))
    (ADDRESS = (PROTOCOL = TCP)(HOST = 192.168.240.173)(PORT = 1521))
    (CONNECT_DATA =
      (SERVER = DEDICATED)
      (SERVICE_NAME = orcl)
    )
  )




t.py

#!python

import cx_Oracle
con = cx_Oracle.connect('pythonhol/welcome@db')
cur = con.cursor()
cur.execute('SELECT  host_name FROM    v$instance')
for result in cur:
    print result
cur.close()
con.close()