我的第一个Python程序--批量生成Oracle DDL文件

一个月之前, 我带人完成了我的第一个Java项目, 部署在Linux平台上. 二十天前, 我写了几个bash shell脚本(start from scratch).  昨天, 我写好了我的第一个python程序. 有点老树开花的感觉嘛!
稍微评论一下这几个语言:
Java语言有点落后, 语法拖沓. 但社区真强大, 有很多优秀的类库包, 有很好的论坛, 博客文章.
Python语言我喜欢, 写法灵活, 网上讲python上手快, 我倒不这么认为, 我觉得需要有很好的感觉才能领悟和驾驭,  因此注定只能是一种小众语言. 

这个程序是生成Oracle数据库对象的DDL脚本. Python版本为2.7, 使用了cx_Oracle包来访问数据库, 版本为cx_Oracle-5.1,  生成DDL部分是使用了Oracle的存储过程DBMS_METADATA.GET_DDL(). (注: cx_Oracle真不好装, 我在Linux上用源码装成功了, 但在Windows下装好后, 却怎么也用不起来. )

该程序支持命令行参数的形式,  共4个参数:
connection参数, 指定连接字符串, 形式为user/pwd@tns
owner参数[可缺省], 指定数据库对象的Owner, 如缺省, 则输出的Owner为connection中的的User.
argObjectInFile参数[可缺省], 指定数据库对象的名, 每行一个对象名, 如缺省, 则输出指定Owner下的所有的对象
argOutputPath参数, 指定生成DDL文件的存放路径. 

代码:

#/usr/bin/env python

'''
Created on 2011-9-23

@author: Harry Chinese
'''

import cx_Oracle 
import sys 


class OraDdlGenerator:
    
    def __init__(self):
        self.argConnect=""
        self.argOwner=""
        self.argObjectInFile=""
        self.argOutputPath="" 
        self.objectList=[]
        
        
    def getObjectList(self):
        objectList=[] 
        try:
            with open(self.argObjectInFile, "r") as text_file:
                for row in text_file: 
                    objectList.append(row.strip().upper())
        except Exception as ex:
            print(ex) 
     
        return objectList
     
    
    
    def composeSQL(self):
        sql="""SELECT  DBMS_METADATA.GET_DDL(AO.OBJECT_TYPE , AO.OBJECT_NAME, AO.OWNER) DDL_DEF,  AO.OWNER||'.'||AO.OBJECT_NAME FULL_OBJECT_NAME   FROM ALL_OBJECTS  AO
            WHERE 1=1
            AND AO.STATUS='VALID' 
            AND AO.OWNER like :Owner 
            AND AO.OBJECT_NAME LIKE :ObjectName
            AND AO.OWNER NOT IN --to filter out the system schema 
            ( 
            'PUBLIC'
            ,'SYSTEM'
            ,'SYS'
            ,'EXFSYS'
            ,'WMSYS'
            ,'DBSNMP'
            ,'OUTLN'
            ,'ORACLE_OCM'
            ,'ORAAUD'
            )
            AND AO.OBJECT_TYPE IN --DBMS_METADATA.GET_DDL() does not support PACKAGE BODY
            (
            ''
            ,'PROCEDURE'
            ,'TABLE'
            ,'INDEX'
            ,'TYPE'
            ,'VIEW'
            ,'FUNCTION'
            --,'PACKAGE BODY'  
            ,'PACKAGE'
            ,'SEQUENCE'
            )
            """
        return sql
    
    
    def saveDdlToFile(self, fullObjectName, DdlStatement):
        fullFileName="{path}//{fullObjectName}.sql".format(path=self.argOutputPath,fullObjectName=fullObjectName)
        with open(fullFileName, "w") as text_file:
            text_file.write(DdlStatement)
    
    
    def saveRowset(self, cursor):
        rows=cursor.fetchall()
        for DDL_DEF, FULL_OBJECT_NAME in rows:
            #print(DDL_DEF)
            self.saveDdlToFile(FULL_OBJECT_NAME, DDL_DEF)
         
 
    
    def saveDDL(self):
        try:
            connection = cx_Oracle.Connection(self.argConnect)
            generator.normalizeArguments(connection) 
            connection.outputtypehandler = self.OutputTypeHandler
            cursor = connection.cursor()
            sql=self.composeSQL()
            
            if (self.argObjectInFile==""):
                cursor.execute(sql, {'Owner':self.argOwner, 'ObjectName':"%"})
                self.saveRowset(cursor)
            else:
                for object in self.objectList:
                    cursor.execute(sql, {'Owner':self.argOwner, 'ObjectName':object})
                    self.saveRowset(cursor)
        except Exception as ex:
            print ex
        finally:
            if (cursor!=None):
                cursor.close()
            if (connection != None):
                connection.close()    
      

    
        
    def OutputTypeHandler(self, cursor, name, defaultType, size, precision, scale):
        if defaultType == cx_Oracle.CLOB:
            return cursor.var(cx_Oracle.LONG_STRING, 900000, cursor.arraysize)
        if defaultType == cx_Oracle.BLOB:
            return cursor.var(cx_Oracle.LONG_BINARY, 900000, cursor.arraysize)



    def normalizeArguments(self, connection):
        if (self.argOwner=="*"):
            self.argOwner="%"
        elif (self.argOwner=="") and (connection!=None):
            self.argOwner=connection.username              
        if (self.argObjectInFile!=""):
            self.objectList= self.getObjectList()
        self.argOwner=self.argOwner.upper()
            
            
        
        
    
    def printUsage(self):
        usage="""OraDdlGenerator is to generate DDL script file for Oracle Object.
Usage:
   OraDdlGenerator connection=user/pwd@tns owner=ownerName objects_in_file=in_file output_path=path
Remark:
   1. If owner=*, it means it will this utility will export objects under all users schema 
   2. If owner option omitted, it means owner=connection.user  
   3. If objects_in_file option omitted, it means this utility will export all objects under the owner schema"""   
        print(usage)


 
    def parseArguments(self):
        #sys.argv = ["myscript.py", "connection=edwuser/edwuser@sdbtest", "owner=s", "objects_in_file=/home/edwuser/1.txt", "output_path=/home/edwuser/output"]
        cmdln_args=sys.argv[1:]
        #print(cmdln_args)
        argKeyValues=dict([arg.split("=") for arg in cmdln_args])
        """
        for arg in argKeyValues.iteritems():
            print(arg)
        """ 
        self.argConnect=argKeyValues["connection"]
         
        self.argOutputPath=argKeyValues["output_path"]
        
        if (argKeyValues.has_key("owner")):
            self.argOwner=argKeyValues["owner"]
        
        if (argKeyValues.has_key("objects_in_file")):
            self.argObjectInFile=argKeyValues["objects_in_file"]

        
        
        
        
if __name__=="__main__":
    generator=OraDdlGenerator()
    parsed=False    
    try:
        generator.parseArguments()
        parsed=True
    except Exception as ex:
        print("Argument parse failed.")
        generator.printUsage()
    if(parsed):               
        generator.saveDDL()
        print("............done")