5.5 x86
Python 基礎語法參考：
Python 基礎語法知識
一. cx_
Python 連線 資料庫，需要使用cx_Oracle 包。
該包的下載地址：.sourceforge.net/
下載的時候，注意版本，對不同版本的 和平臺，都有不同的cx_Oracle。
[root@rac1 u01]# rpm -ivh cx_-5.1-10g-py24-1.i386.rpm
Preparing... ########################################### [100%]
1:cx_Oracl ########################################### [100%]
Linux 平臺下，用root 使用者進行安裝，並且還需要將一些 的環境變數新增到root使用者的.bash_profile 裡。
最簡單的方法，就是直接把 使用者的變數copy過來：
PATH=$PATH:$HOME/bin
export _BASE=/u01/app/oracle
export _HOME=$ORACLE_BASE/product/10.2.0/db_1
export ORA_CRS_HOME=$_BASE/product/crs
export _SID=dave1
export PATH=.:${PATH}:$HOME/bin:$_HOME/bin:$ORA_CRS_HOME/bin
export PATH=${PATH}:/usr/bin:/bin:/usr/bin/X11:/usr/local/bin
export PATH=${PATH}:$_BASE/common/oracle/bin
export _TERM=xterm
export TNS_ADMIN=$_HOME/network/admin
export ORA_NLS10=$_HOME/nls/data
export LD_LIBRARY_PATH=$_HOME/lib
export LD_LIBRARY_PATH=${LD_LIBRARY_PATH}:$_HOME/oracm/lib
export LD_LIBRARY_PATH=${LD_LIBRARY_PATH}:/lib:/usr/lib:/usr/local/lib
export CLASSPATH=$_HOME/JRE
export CLASSPATH=${CLASSPATH}:$_HOME/jlib
export CLASSPATH=${CLASSPATH}:$_HOME/rdbms/jlib
export CLASSPATH=${CLASSPATH}:$_HOME/network/jlib
export THREADS_FLAG=native
export TEMP=/tmp
export TMPDIR=/tmp
然後source 應用一下。
二. Python 連 的基本操作
2.1 DB連線和關閉DB連線
2.1.1 方法一：使用者名稱，密碼和監聽 分開寫
[root@rac1 u01]# cat db.py
import cx_
db=cx_.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：使用者名稱，密碼和監聽寫在一起
[root@rac1 u01]# cat db.py
import cx_
db=cx_.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：配置監聽並連線
[root@rac1 u01]# cat db.py
import cx_
tns=cx_.makedsn('rac1',1521,'dave1')
db=cx_.connect('system','oracle',tns)
print tns
print db.version
vs=db.version.split('.')
print vs
if vs[0]=='10':
print "This is 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 10g!
2.2 建立cursor 並執行SQL語句
[root@rac1 u01]# cat db.py
import cx_
tns=cx_.makedsn('rac1',1521,'dave1')
db=cx_.connect('system','oracle',tns) --建立連線
cr=db.cursor() --建立cursor
sql='select * from phone'
cr.execute(sql) --執行sql 語句
print "\nThis is Fetchall!"
rs=cr.fetchall() --一次返回所有結果集
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
--使用引數查詢
print "\n select with parameter:"
pr={'id':3,'tel':13888888888}
cr.execute('select * from phone where id=:id or phone=:tel',pr)
--這裡我們將引數作為一個字典來處理的
rs=cr.fetchall()
print rs
cr.execute('select * from phone where id=:myid or phone=:myphone',myid=2,myphone=13888888888)
--這裡我們直接寫引數
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 型別和 型別的對應關係：
During the fetch stage, basic 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:
|
cx_ |
Python | |
|
VARCHAR2 |
cx_.STRING |
str |
|
CHAR |
cx_.FIXED_CHAR | |
|
NUMBER |
cx_.NUMBER |
int |
|
FLOAT |
float | |
|
DATE |
cx_.DATETIME |
datetime.datetime |
|
TIMESTAMP |
cx_.TIMESTAMP | |
|
CLOB |
cx_.CLOB |
cx_.LOB |
三. 一個完成的示例
在這個例子裡，我們將用Python 對DB 進行一些操作，包括，建立一張表，並插入一些資料，在修改其中的部分資料。
[root@rac1 u01]# cat dave.py
#!/usr/bin/python
#coding=utf-8
import cx_
import sys
import urllib
import os
def connectDB(dbname='dave'):
if dbname=='dave':
connstr='system/@192.168.2.42:1521/dave'
db=cx_.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':'','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, '', 13888888888L)
(4, 'anqing', 13888888888L)
change the nanme to anhui where id equal 1,and select the result
(1, 'anhui', 13888888888L)
(2, 'dave', 138888888888L)
(3, '', 13888888888L)
(4, 'anqing', 13888888888L)
delete the data where id equal 3 and select the result
(1, 'anhui', 13888888888L)
(2, 'dave', 138888888888L)
(4, 'anqing', 13888888888L)
關於Python 連線 資料庫，及一些基本操作，就這麼多。