Python使用PyGreSQL操作PostgreSQL数据库教程

2019-10-06 10:28:42于丽

PostgreSQL是一款功能强大的开源关系型数据库,本文使用python实现了对开源数据库PostgreSQL的常用操作,其开发过程简介如下:

一、环境信息:

   1、操作系统:

        RedHat Enterprise Linux 4
        Windows XP SP2

  2、数据库:

        PostgreSQL8.3

  3、 开发工具:

        Eclipse+Pydev+python2.6+PyGreSQL(提供pg模块)

  4、说明:

        a、PostgreSQL数据库运行于RedHat Linux上,Windows下也要安装pgAdmin(访问PostgreSQL服务器的客户端)。
        b、PyGreSQL(即pg)模块下载路径及API手册:http://www.pygresql.org/
 PyGreSQL模块点此本站下载

二、配置:

       1、将pgAdmin安装路径下以下子目录添加到系统环境变量中:

             E:Program FilesPostgreSQL8.3lib

             E:Program FilesPostgreSQL8.3bin

       2、将python安装目录C:Python26Libsite-packagespywin32_system32下的dll文件拷贝到C:WINDOWSsystem32

       3、说明:如果跳过以上两步,在import pg时将会报错,并且会浪费较长时间才能搞定。

三、程序实现:

#!/usr/bin/env python
# -*- coding: utf-8 -*-

#导入日志及pg模块
import logging
import logging.config
import pg

#日志配置文件名
LOG_FILENAME = 'logging.conf'

#日志语句提示信息
LOG_CONTENT_NAME = 'pg_log'

def log_init(log_config_filename, logname):
  '''
  Function:日志模块初始化函数
  Input:log_config_filename:日志配置文件名
      lognmae:每条日志前的提示语句
  Output: logger
  author: socrates
  date:2012-02-12
  '''
  logging.config.fileConfig(log_config_filename)
  logger = logging.getLogger(logname)
  return logger

def operate_postgre_tbl_product():
  '''
  Function:操作pg数据库函数
  Input:NONE
  Output: NONE
  author: socrates
  date:2012-02-12
  ''' 
  pgdb_logger.debug("operate_postgre_tbl_product enter...") 
  
  #连接数据库 
  try:
    pgdb_conn = pg.connect(dbname = 'kevin_test', host = '192.168.230.128', user = 'dyx1024', passwd = '888888')
  except Exception, e:
     print e.args[0]
     pgdb_logger.error("conntect postgre database failed, ret = %s" % e.args[0])  
     return  
   
  pgdb_logger.info("conntect postgre database(kevin_test) succ.") 
    
  #删除表
  sql_desc = "DROP TABLE IF EXISTS tbl_product3;"
  try:
    pgdb_conn.query(sql_desc)
  except Exception, e:
    print 'drop table failed'
    pgdb_logger.error("drop table failed, ret = %s" % e.args[0])
    pgdb_conn.close() 
    return
  
  pgdb_logger.info("drop table(tbl_product3) succ.") 
 
  #创建表
  sql_desc = '''CREATE TABLE tbl_product3(
    i_index INTEGER,
    sv_productname VARCHAR(32)
    );'''
  try:  
    pgdb_conn.query(sql_desc)
  except Exception, e:
    print 'create table failed'
    pgdb_logger.error("create table failed, ret = %s" % e.args[0])
    pgdb_conn.close() 
    return    
  
  pgdb_logger.info("create table(tbl_product3) succ.") 
   
  #插入记录  
  sql_desc = "INSERT INTO tbl_product3(sv_productname) values('apple')"
  try:
    pgdb_conn.query(sql_desc)
  except Exception, e:
    print 'insert record into table failed'
    pgdb_logger.error("insert record into table failed, ret = %s" % e.args[0])
    pgdb_conn.close() 
    return  
   
  pgdb_logger.info("insert record into table(tbl_product3) succ.")   
   
  #查询表 1    
  sql_desc = "select * from tbl_product3"
  for row in pgdb_conn.query(sql_desc).dictresult():
    print row
    pgdb_logger.info("%s", row) 
 
  #查询表2    
  sql_desc = "select * from tbl_test_port"
  for row in pgdb_conn.query(sql_desc).dictresult():
    print row 
    pgdb_logger.info("%s", row)    
   
  #关闭数据库连接   
  pgdb_conn.close()    
  pgdb_logger.debug("operate_sqlite3_tbl_product leaving...") 

if __name__ == '__main__': 
  
  #初始化日志系统
  pgdb_logger = log_init(LOG_FILENAME, LOG_CONTENT_NAME)  
  
  #操作数据库
  operate_postgre_tbl_product()