Python:操作PostgreSQL数据库(使用DB API2.0)

 

分类： 数据库 Python 脚本语言 PostgreSQL2012-02-14 00:10 546人阅读 评论(0) 收藏 举报

   昨天在《Python:操作PostgreSQL数据库(使用PyGreSQL)》一文中使用PyGreSQL模块实现了对PostgreSQL数据库的操作，今天使用另一种python通用的数据库访问接口DB API2.0来实现一下同样的操作，其实在《Python:操作嵌入式数据库SQLite》一文中我们使用的就是DB API2.0，我们可以看到，它对不同数据库提供了统一的访问接口，更多关于DB API2.0的介绍请参考http://www.python.org/dev/peps/pep-0249/

   来看看实现，首先我们要下载提供DB API2.0接口的模块psycopg2,路径：http://initd.org/psycopg/download/，此模块API手册地址为：http://initd.org/psycopg/docs/index.html

一、实现：

 

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

#导入日志及psycopg2模块
import logging
import logging.config
import psycopg2

#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:2012-02-13
    '''
    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:2012-02-13
    '''
    pgdb_logger.debug("operate_postgre_tbl_product enter...")

    #连接数据库
    try:
        pgdb_conn = psycopg2.connect(database = 'kevin_test', user = 'dyx1024', password = '888888', host = '192.168.230.128')
    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.")

    pg_cursor = pgdb_conn.cursor()

    #删除表
    sql_desc = "DROP TABLE IF EXISTS tbl_product3;"
    try:
        pg_cursor.execute(sql_desc)
    except Exception, e:
        print 'drop table failed'
        pgdb_logger.error("drop table failed, ret = %s" % e.args[0])
        pg_cursor.close()
        pgdb_conn.close()
        return
    pgdb_conn.commit()

    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:
        pg_cursor.execute(sql_desc)
    except Exception, e:
        print 'create table failed'
        pgdb_logger.error("create table failed, ret = %s" % e.args[0])
        pg_cursor.close()
        pgdb_conn.close()
        return
    pgdb_conn.commit()

    pgdb_logger.info("create table(tbl_product3) succ.")

    #插入记录
    sql_desc = "INSERT INTO tbl_product3(sv_productname) values('apple')"
    try:
        pg_cursor.execute(sql_desc)
    except Exception, e:
        print 'insert record into table failed'
        pgdb_logger.error("insert record into table failed, ret = %s" % e.args[0])
        pg_cursor.close()
        pgdb_conn.close()
        return
    pgdb_conn.commit()

    pgdb_logger.info("insert record into table(tbl_product3) succ.")

    #查询表方法一
    sql_desc = "select * from tbl_product3"
    try:
        pg_cursor.execute(sql_desc)
    except Exception, e:
        print 'select record from  table tbl_product3 failed'
        pgdb_logger.error("select record from  table tbl_product3 failed, ret = %s" % e.args[0])
        pg_cursor.close()
        pgdb_conn.close()
        return

    for row in pg_cursor:
        print row
        pgdb_logger.info("%s", row)

    print '*' * 20
    #查询表方法二
    sql_desc = "select * from tbl_test_port"
    try:
        pg_cursor.execute(sql_desc)
    except Exception, e:
        print 'select record from  table tbl_test_port failed'
        pgdb_logger.error("select record from  table tbl_test_port failed, ret = %s" % e.args[0])
        pg_cursor.close()
        pgdb_conn.close()
        return

    for row in pg_cursor.fetchall():
        print row
        pgdb_logger.info("%s", row)

    #关闭数据库连接
    pg_cursor.close()
    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()

二、测试：

 

1、命令行结果：

 

(None, 'apple')
********************
(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)

2、日志文件结果：

 

 

[2012-02-14 00:12:06,358  pg_log]DEBUG:  operate_postgre_tbl_product enter... (db_postgre.py:36)
[2012-02-14 00:12:06,453  pg_log]INFO:  conntect postgre database(kevin_test) succ. (db_postgre.py:46)
[2012-02-14 00:12:06,467  pg_log]INFO:  drop table(tbl_product3) succ. (db_postgre.py:62)
[2012-02-14 00:12:06,483  pg_log]INFO:  create table(tbl_product3) succ. (db_postgre.py:79)
[2012-02-14 00:12:06,483  pg_log]INFO:  insert record into table(tbl_product3) succ. (db_postgre.py:93)
[2012-02-14 00:12:06,483  pg_log]INFO:  (None, 'apple') (db_postgre.py:108)
[2012-02-14 00:12:06,483  pg_log]INFO:  (1, 2, 1) (db_postgre.py:124)
[2012-02-14 00:12:06,483  pg_log]INFO:  (2, 3, 1) (db_postgre.py:124)
[2012-02-14 00:12:06,483  pg_log]INFO:  (3, 5, 1) (db_postgre.py:124)
[2012-02-14 00:12:06,483  pg_log]INFO:  (5, 0, 1) (db_postgre.py:124)
[2012-02-14 00:12:06,483  pg_log]INFO:  (7, 18, 1) (db_postgre.py:124)
[2012-02-14 00:12:06,500  pg_log]INFO:  (8, 8, 1) (db_postgre.py:124)
[2012-02-14 00:12:06,500  pg_log]INFO:  (9, 7, 1) (db_postgre.py:124)
[2012-02-14 00:12:06,500  pg_log]INFO:  (10, 21, 1) (db_postgre.py:124)
[2012-02-14 00:12:06,500  pg_log]INFO:  (11, 23, 1) (db_postgre.py:124)
[2012-02-14 00:12:06,500  pg_log]INFO:  (12, 29, 1) (db_postgre.py:124)
[2012-02-14 00:12:06,500  pg_log]INFO:  (4, 3000, 1) (db_postgre.py:124)
[2012-02-14 00:12:06,500  pg_log]INFO:  (6, 1999, 1) (db_postgre.py:124)
[2012-02-14 00:12:06,500  pg_log]DEBUG:  operate_sqlite3_tbl_product leaving... (db_postgre.py:130)