Python 连接 Oracle 示例

RedHat  5.5 x86

Python 基础语法参考：

       Python 基础语法知识

http://www.linuxidc.com/Linux/2011-04/34055.htm 

一.  cx_Oracle

       Python 连接Oracle 数据库，需要使用cx_Oracle 包。

       该包的下载地址：http://cx-Oracle.sourceforge.net/

       下载的时候，注意版本，对不同版本的Oracle 和平台，都有不同的cx_Oracle。

      [root@rac1 u01]# rpm -ivh cx_Oracle-5.1-10g-py24-1.i386.rpm

         Preparing...       ########################################### [100%]

            1:cx_Oracl     ########################################### [100%]

       Linux 平台下，用root 用户进行安装，并且还需要将一些Oracle 的环境变量添加到root用户的.bash_profile 里。

       最简单的方法，就是直接把Oracle 用户的变量copy过来：

PATH=$PATH:$HOME/bin

export Oracle_BASE=/u01/app/oracle

export Oracle_HOME=$ORACLE_BASE/product/10.2.0/db_1

export ORA_CRS_HOME=$Oracle_BASE/product/crs

export Oracle_SID=dave1

export PATH=.:${PATH}:$HOME/bin:$Oracle_HOME/bin:$ORA_CRS_HOME/bin

export PATH=${PATH}:/usr/bin:/bin:/usr/bin/X11:/usr/local/bin

export PATH=${PATH}:$Oracle_BASE/common/oracle/bin

export Oracle_TERM=xterm

export TNS_ADMIN=$Oracle_HOME/network/admin

export ORA_NLS10=$Oracle_HOME/nls/data

export LD_LIBRARY_PATH=$Oracle_HOME/lib

export LD_LIBRARY_PATH=${LD_LIBRARY_PATH}:$Oracle_HOME/oracm/lib

export LD_LIBRARY_PATH=${LD_LIBRARY_PATH}:/lib:/usr/lib:/usr/local/lib

export CLASSPATH=$Oracle_HOME/JRE

export CLASSPATH=${CLASSPATH}:$Oracle_HOME/jlib

export CLASSPATH=${CLASSPATH}:$Oracle_HOME/rdbms/jlib

export CLASSPATH=${CLASSPATH}:$Oracle_HOME/network/jlib

export THREADS_FLAG=native

export TEMP=/tmp

export TMPDIR=/tmp

然后source 应用一下。

二.  Python 连Oracle 的基本操作

2.1  DB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

[root@rac1 u01]# cat db.py

import cx_Oracle

db=cx_Oracle.connect('system','oracle','192.168.2.42:1521/dave')

print db.version

db.close()

[root@rac1 u01]# 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

[root@rac1 u01]# cat db.py

import cx_Oracle

db=cx_Oracle.connect('system/oracle@192.168.2.42:1521/dave')

print db.version

db.close()

[root@rac1 u01]# python db.py

10.2.0.1.0

2.1.3 方法三：配置监听并连接

[root@rac1 u01]# 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[0]=='10':

   print "This is Oracle 10g!"

db.close()

[root@rac1 u01]# 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

[root@rac1 u01]# 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()

[root@rac1 u01]# 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。

[root@rac1 u01]# 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()

[root@rac1 u01]# 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。