Python 连接 Oracle 示例
二.Python 连Oracle 的基本操作2.1DB连接和关闭DB连接
2.1.1 方法一：用户名，密码和监听 分开写
# cat db.py
import cx_Oracle
db=cx_Oracle.connect('system','oracle','192.168.2.42:1521/dave')
print db.version
db.close()
# python db.py
10.2.0.1.0
2.1.2 方法二：用户名，密码和监听写在一起
# cat db.py
import cx_Oracle
db=cx_Oracle.connect('system/oracle@192.168.2.42:1521/dave')
print db.version
db.close()
# python db.py
10.2.0.1.0
2.1.3 方法三：配置监听并连接
# cat db.py
import cx_Oracle
tns=cx_Oracle.makedsn('rac1',1521,'dave1')
db=cx_Oracle.connect('system','oracle',tns)
print tns
print db.version
vs=db.version.split('.')
print vs
if vs=='10':
print "This is Oracle 10g!"
db.close()
# python db.py
(DESCRIPTION=(ADDRESS_LIST=(ADDRESS=(PROTOCOL=TCP)(HOST=rac1)(PORT=1521)))(CONNECT_DATA=(SID=dave1)))
10.2.0.1.0
['10', '2', '0', '1', '0']
This is Oracle 10g!
2.2建立cursor 并执行SQL语句
# cat db.py
import cx_Oracle
tns=cx_Oracle.makedsn('rac1',1521,'dave1')
db=cx_Oracle.connect('system','oracle',tns) --创建连接
cr=db.cursor()--创建cursor
sql='select * from phone'
cr.execute(sql)--执行sql 语句
print "\nThis is Fetchall!"
rs=cr.fetchall()--一次返回所有结果集
print "print all:(%s)" %rs
print "\n print by row:"
for x in rs:
print x
print "\nThis is Fetone!"
cr.execute(sql)
while(1):
rs=cr.fetchone()--一次返回一行
if rs ==None:break
print rs
--使用参数查询
print "\n select with parameter:"
pr={'id':3,'tel':13888888888}
cr.execute('select * from phone where id=:id or phone=:tel',pr)
--这里我们将参数作为一个字典来处理的
rs=cr.fetchall()
print rs
cr.execute('select * from phone where id=:myid or phone=:myphone',myid=2,myphone=13888888888)
--这里我们直接写参数
rs=cr.fetchall()
print rs
cr.close()
db.close()
# python db.py
This is Fetchall!
print all:([(1, 13865999999L), (2, 13888888888L)])
print by row:
(1, 13865999999L)
(2, 13888888888L)
This is Fetone!
(1, 13865999999L)
(2, 13888888888L)
select with parameter:
[(2, 13888888888L)]
[(2, 13888888888L)]
Python 类型和Oracle 类型的对应关系：
During the fetch stage, basic Oracle data types get mapped into their Python equivalents. cx_Oracle maintains a separate set of data types that helps in this transition. The Oracle - cx_Oracle - Python mappings are:
Oracle
cx_Oracle
Python
VARCHAR2
NVARCHAR2
LONG
cx_Oracle.STRING
str
CHAR
cx_Oracle.FIXED_CHAR
NUMBER
cx_Oracle.NUMBER
int
FLOAT
float
DATE
cx_Oracle.DATETIME
datetime.datetime
TIMESTAMP
cx_Oracle.TIMESTAMP
CLOB
cx_Oracle.CLOB
cx_Oracle.LOB
三. 一个完成的示例
在这个例子里，我们将用Python 对DB 进行一些操作，包括，创建一张表，并插入一些数据，在修改其中的部分数据。
# cat dave.py
#!/usr/bin/python
#coding=utf-8
import cx_Oracle
import sys
import urllib
import os
def connectDB(dbname='dave'):
if dbname=='dave':
connstr='system/Oracle@192.168.2.42:1521/dave'
db=cx_Oracle.connect(connstr)
return db
def sqlSelect(sql,db):
#include:select
cr=db.cursor()
cr.execute(sql)
rs=cr.fetchall()
cr.close()
return rs
def sqlDML(sql,db):
#include: insert,update,delete
cr=db.cursor()
cr.execute(sql)
cr.close()
db.commit()
def sqlDML2(sql,params,db):
# execute dml with parameters
cr=db.cursor()
cr.execute(sql,params)
cr.close()
db.commit()
def sqlDDL(sql,db):
#include: create
cr=db.cursor()
cr.execute(sql)
cr.close()
if __name__=='__main__':
print "This is a test python program,write by tianlesoftware!\n"
os.environ['NLS_LANG']='SIMPLIFIED CHINESE_CHINA.UTF8'
#connect to database:
db=connectDB()
#create a table:
sql='create table dave(id number,name varchar2(20),phone number)'
sqlDDL(sql,db)
#insert data to table dave:
sql='insert into dave values(1,\'tianlesoftware\',13888888888)'
sqlDML(sql,db)
dt=[{'id':2,'name':'dave','phone':138888888888},
{'id':3,'name':'Oracle','phone':13888888888},
{'id':4,'name':'anqing','phone':13888888888}]
sql='insert into dave values(:id,:name,:phone)'
for x in dt:
sqlDML2(sql,x,db)
#select the result:
print "this is the first time select the data from dave"
sql='select * from dave'
rs=sqlSelect(sql,db)
for x in rs:
print x
#update data where id=1,change the name to anhui
sql='update dave set name=\'anhui\' where id=1'
sqlDML(sql,db)
#select again:
print "\n change the nanme to anhui where id equal 1,and select the result"
sql='select * from dave'
rs=sqlSelect(sql,db)
for x in rs:
print x
#delete data where id=3
sql='delete from dave where id=3'
sqlDML(sql,db)
#select again:
print "\n delete the data where id equal 3 and select the result"
sql='select * from dave'
rs=sqlSelect(sql,db)
for x in rs:
print x
db.close()
# python dave.py
This is a test python program,write by tianlesoftware!
this is the first time select the data from dave
(1, 'tianlesoftware', 13888888888L)
(2, 'dave', 138888888888L)
(3, 'Oracle', 13888888888L)
(4, 'anqing', 13888888888L)
change the nanme to anhui where id equal 1,and select the result
(1, 'anhui', 13888888888L)
(2, 'dave', 138888888888L)
(3, 'Oracle', 13888888888L)
(4, 'anqing', 13888888888L)
delete the data where id equal 3 and select the result
(1, 'anhui', 13888888888L)
(2, 'dave', 138888888888L)
(4, 'anqing', 13888888888L)
关于Python 连接Oracle 数据库，及一些基本操作，就这么多。
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