Python使用PyGreSQL操作PostgreSQL資料庫教程_python

PostgreSQL是一款功能強大的開源關係型資料庫，本文使用python實現了對開來源資料庫PostgreSQL的常用操作，其開發過程簡介如下：

一、環境資訊：

   1、作業系統：

        RedHat Enterprise Linux 4
        Windows XP SP2

  2、資料庫：

        PostgreSQL8.3

  3、 開發工具:

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

  4、說明：

        a、PostgreSQL資料庫運行於RedHat Linux上，Windows下也要安裝pgAdmin（訪問PostgreSQL伺服器的用戶端）。
        b、PyGreSQL(即pg)模組下載路徑及API手冊：http://www.pygresql.org/
 PyGreSQL模組點此本站下載

二、配置：

       1、將pgAdmin安裝路徑下以下子目錄添加到系統內容變數中:

             E:\Program Files\PostgreSQL\8.3\lib

             E:\Program Files\PostgreSQL\8.3\bin

       2、將python安裝目錄C:\Python26\Lib\site-packages\pywin32_system32下的dll檔案拷貝到C:\WINDOWS\system32

       3、說明：如果跳過以上兩步，在import pg時將會報錯，並且會浪費較長時間才能搞定。

三、程式實現：

#!/usr/bin/env python# -*- coding: utf-8 -*-#匯入日誌及pg模組import loggingimport logging.configimport pg#日誌設定檔名LOG_FILENAME = 'logging.conf'#日誌語句提示資訊LOG_CONTENT_NAME = 'pg_log'def log_init(log_config_filename, logname):  '''  Function:日誌模組初始化函數  Input：log_config_filename:日誌設定檔名      lognmae:每條日誌前的提示句  Output: logger  author: socrates  date:2012-02-12  '''  logging.config.fileConfig(log_config_filename)  logger = logging.getLogger(logname)  return loggerdef operate_postgre_tbl_product():  '''  Function:操作pg資料庫函數  Input：NONE  Output: NONE  author: socrates  date:2012-02-12  '''   pgdb_logger.debug("operate_postgre_tbl_product enter...")     #串連資料庫   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.")       #刪除表  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.")    #建立表  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.")      #插入記錄    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.")        #查詢表 1      sql_desc = "select * from tbl_product3"  for row in pgdb_conn.query(sql_desc).dictresult():    print row    pgdb_logger.info("%s", row)    #查詢表2      sql_desc = "select * from tbl_test_port"  for row in pgdb_conn.query(sql_desc).dictresult():    print row     pgdb_logger.info("%s", row)         #關閉資料庫連接     pgdb_conn.close()      pgdb_logger.debug("operate_sqlite3_tbl_product leaving...") if __name__ == '__main__':     #初始化日誌系統  pgdb_logger = log_init(LOG_FILENAME, LOG_CONTENT_NAME)      #操作資料庫  operate_postgre_tbl_product()  

四、測試：

 1、運行後命令列列印結果：

{'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、記錄檔內容：

[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查看結果：

[root@kevin ~]# su - postgres[postgres@kevin ~]$ psql -U dyx1024 -d kevin_testpsql (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 ~]$