Python:操作PostgreSQL数

2023-01-31 02:01:31 python postgresql 操作

  昨天使用python写了操作嵌入式数据库sqlite的方法,今天用Python写了针对个人比较熟悉的开源数据库postgresql的常用操作,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/

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 Files\PostgreSQL\8.3\lib

             E:\Program Files\PostgreSQL\8.3\bin

       2、将python安装目录C:\Python26\Lib\site-packages\pywin32_system32下的dll文件拷贝到C:\WINDOWS\system32

       3、说明:

              a. 如果跳过以上两步,在import pg时将会报错,浪费较长时间才搞定。

              b. 如果对PostgreSQL安装和配置不熟悉,请参考本博客中以下几篇文章:

                  《RedHat Linux上安装PostgreSQL》

                  《PostgreSQL服务端监听设置及客户端连接方法》

                  《PostgreSQL数据库创建、删除方法》

                   更多PostgreSQL相关知识请访问从我的博客专栏:PostgreSQL系列

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()
    

四、测试

 1、运行后命令行打印结果:

{'sv_productname': 'apple', 'i_index': None}
{'i_status': 1, 'i_port': 2, 'i_index': 1}
{'i_status': 1, 'i_port': 3, 'i_index': 2}
{'i_status': 1, 'i_port': 5, 'i_index': 3}
{'i_status': 1, 'i_port': 0, 'i_index': 5}
{'i_status': 1, 'i_port': 18, 'i_index': 7}
{'i_status': 1, 'i_port': 8, 'i_index': 8}
{'i_status': 1, 'i_port': 7, 'i_index': 9}
{'i_status': 1, 'i_port': 21, 'i_index': 10}
{'i_status': 1, 'i_port': 23, 'i_index': 11}
{'i_status': 1, 'i_port': 29, 'i_index': 12}
{'i_status': 1, 'i_port': 3000, 'i_index': 4}
{'i_status': 1, 'i_port': 1999, 'i_index': 6}
 2、日志文件内容:

[2012-02-12 18:09:53,536  pg_log]DEBUG:  operate_postgre_tbl_product enter... (test_func.py:36)
[2012-02-12 18:09:53,772  pg_log]INFO:  conntect postgre database(kevin_test) succ. (test_func.py:46)
[2012-02-12 18:09:53,786  pg_log]INFO:  drop table(tbl_product3) succ. (test_func.py:58)
[2012-02-12 18:09:53,802  pg_log]INFO:  create table(tbl_product3) succ. (test_func.py:73)
[2012-02-12 18:09:53,802  pg_log]INFO:  insert record into table(tbl_product3) succ. (test_func.py:85)
[2012-02-12 18:09:53,802  pg_log]INFO:  {'sv_productname': 'apple', 'i_index': None} (test_func.py:91)
[2012-02-12 18:09:53,802  pg_log]INFO:  {'i_status': 1, 'i_port': 2, 'i_index': 1} (test_func.py:97)
[2012-02-12 18:09:53,802  pg_log]INFO:  {'i_status': 1, 'i_port': 3, 'i_index': 2} (test_func.py:97)
[2012-02-12 18:09:53,802  pg_log]INFO:  {'i_status': 1, 'i_port': 5, 'i_index': 3} (test_func.py:97)
[2012-02-12 18:09:53,802  pg_log]INFO:  {'i_status': 1, 'i_port': 0, 'i_index': 5} (test_func.py:97)
[2012-02-12 18:09:53,819  pg_log]INFO:  {'i_status': 1, 'i_port': 18, 'i_index': 7} (test_func.py:97)
[2012-02-12 18:09:53,819  pg_log]INFO:  {'i_status': 1, 'i_port': 8, 'i_index': 8} (test_func.py:97)
[2012-02-12 18:09:53,819  pg_log]INFO:  {'i_status': 1, 'i_port': 7, 'i_index': 9} (test_func.py:97)
[2012-02-12 18:09:53,819  pg_log]INFO:  {'i_status': 1, 'i_port': 21, 'i_index': 10} (test_func.py:97)
[2012-02-12 18:09:53,819  pg_log]INFO:  {'i_status': 1, 'i_port': 23, 'i_index': 11} (test_func.py:97)
[2012-02-12 18:09:53,819  pg_log]INFO:  {'i_status': 1, 'i_port': 29, 'i_index': 12} (test_func.py:97)
[2012-02-12 18:09:53,819  pg_log]INFO:  {'i_status': 1, 'i_port': 3000, 'i_index': 4} (test_func.py:97)
[2012-02-12 18:09:53,819  pg_log]INFO:  {'i_status': 1, 'i_port': 1999, 'i_index': 6} (test_func.py:97)
[2012-02-12 18:09:53,819  pg_log]DEBUG:  operate_sqlite3_tbl_product leaving... (test_func.py:101)

3、psql查看结果:

[root@kevin ~]# su - postgres
[postgres@kevin ~]$ psql -U dyx1024 -d kevin_test
psql (8.4.2)
Type "help" for help.

kevin_test=# \dt
                List of relations
 Schema |     Name      | Type  |     Owner      
--------+---------------+-------+----------------
 public | tbl_product3  | table | dyx1024
 public | tbl_test_port | table | pg_test_user_3
(2 rows)

kevin_test=# select * from tbl_product3;
 i_index | sv_productname 
---------+----------------
         | apple
(1 row)

kevin_test=# select * from tbl_test_port;
 i_index | i_port | i_status 
---------+--------+----------
       1 |      2 |        1
       2 |      3 |        1
       3 |      5 |        1
       5 |      0 |        1
       7 |     18 |        1
       8 |      8 |        1
       9 |      7 |        1
      10 |     21 |        1
      11 |     23 |        1
      12 |     29 |        1
       4 |   3000 |        1
       6 |   1999 |        1
(12 rows)

kevin_test=# \q
[postgres@kevin ~]$ 



  

        

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