python blob操做

最近在學習使用Python，操做Oracle數據庫採用的是cx_Oracle模塊。

對於基本字段，均可以正常操做。可是對於Blob字段，我試試好幾回，都沒成功。下面貼出測試代碼，與你們討論討論。

這是操做的持久對象。本人對Python剛剛接觸，不知道Python有沒有好的ORM框架。

class Report(object):

 selectSql="select RPTID,CLGID,RPTNAME,RPTTYPE,RPTDESC,QUALITYSIGNALS,DISPLAYSETTING,EXCELRANGE,HTMLTEMPLATE from rpt_report order by rptid"

 createTableSql='''
/*==============================================================*/
/* Table: RPT_REPORT */
/*==============================================================*/
create table RPT_REPORT (
 RPTID NUMBER not null,
 CLGID NUMBER,
 RPTNAME VARCHAR2(50) not null,
 RPTTYPE NUMBER not null,
 RPTDESC VARCHAR2(100),
 QUALITYSIGNALS VARCHAR2(50),
 DISPLAYSETTING VARCHAR2(50),
 EXCELRANGE VARCHAR2(30),
 HTMLTEMPLATE BLOB,
 constraint PK_RPT_REPORT primary key (RPTID)
 using index
);
 '''

 deleteSql="delete from rpt_report"

 def __init__(self,RPTID,CLGID,RPTNAME,RPTTYPE,RPTDESC,QUALITYSIGNALS,DISPLAYSETTING,EXCELRANGE,HTMLTEMPLATE):

 self.RPTID=RPTID
 self.CLGID=CLGID
 self.RPTNAME=RPTNAME
 self.RPTTYPE=RPTTYPE
 self.RPTDESC=RPTDESC and RPTDESC or ""
 self.QUALITYSIGNALS=QUALITYSIGNALS and QUALITYSIGNALS or ""
 self.DISPLAYSETTING=DISPLAYSETTING and DISPLAYSETTING or ""
 self.EXCELRANGE=EXCELRANGE and EXCELRANGE or ""
 self.HTMLTEMPLATE=HTMLTEMPLATE and HTMLTEMPLATE or ""

 def gerInsertSQL(self):
 sql="insert into rpt_report(RPTID,CLGID,RPTNAME,RPTTYPE,RPTDESC,QUALITYSIGNALS,DISPLAYSETTING,EXCELRANGE,HTMLTEMPLATE) values (%d,%d,'%s',%d,'%s','%s','%s','%s',:HTMLTEMPLATE)" 
 return sql 

其中，report表的「HTMLTEMPLATE」字段是blob類型。

下面是測試程序。程序的目的主要是完成數據遷移。

import cx_Oracle
import sys
#1.5 database
connection = cx_Oracle.Connection("pw_report/report@tpri")
cursor = connection.cursor()
#2.0 database
conn=cx_Oracle.Connection("pw_report2/report@tpri")
cur=conn.cursor()

cursor.execute(Report.selectSql)

cursor.rowfactory = Report
index=0
isRollback=False


for row in cursor:
 sql=row.gerInsertSQL()
 try:
 HTMLTEMPLATE=row.HTMLTEMPLATE and row.HTMLTEMPLATE or ""

 sql=sql % (row.RPTID,row.CLGID,row.RPTNAME,row.RPTTYPE,row.RPTDESC,row.QUALITYSIGNALS,row.DISPLAYSETTING,row.EXCELRANGE)
 print sql
 cur.setinputsizes(HTMLTEMPLATE=cx_Oracle.BLOB)
 cur.execute(sql,{"HTMLTEMPLATE":HTMLTEMPLATE})

 index+=1
 except cx_Oracle.DatabaseError, exc:
 print "break le 11"
 isRollback=True
 break
 except:
 print "break le 22"
 isRollback=True
 break


print "\n insert data: %d" % index
if isRollback:
 conn.rollback()
else:
 conn.commit()
conn.close()
connection.close()

以上程序，若BLOB字段內容爲空，就能夠執行經過，若不爲空，則沒法插入。


在此與你們分享溝通下。