用两种不同的方法导出ORACLE 查询数据为CSV 文件 （python 代码 与 使用 utl_file 包）

因要对客户发送一些推广邮件，需要把email导出到csv，再使用专门邮件发送软件进行发送。

在使用ORACLE 的 utl_file 包，把数据写到文件中。

看到是逐条数据写入文件。速度比较慢。所以想到python来进行处理。写完后，速度有所改观。

在写成BOLG时，SQL 代码有所修改。

以下是两种方法。

一、安装：cx_Oracle-5.1.3

---------------------------------------------------------------

1 下载地址：
https://pypi.python.org/pypi/cx_Oracle/5.1.3
2 解压：

[oracle@dg1 backup]$ tar -xvf cx_Oracle-5.1.3.tar.gz

3.编译并安装。

[oracle@dg1 cx_Oracle-5.1.3]$ python setup.py build

running build

running build_ext

building 'cx_Oracle' extension

creating build

creating build/temp.linux-x86_64-2.4-11g

gcc -pthread -fno-strict-aliasing -DNDEBUG -O2 -g -pipe -Wall -Wp,-D_FORTIFY_SOURCE=2 -fexceptions -fstack-protector --param=ssp-buffer-size=4 -m64 -mtune=generic -D_GNU_SOURCE -fPIC -fPIC -I/opt/app/oracle/product/11.2.0/rdbms/demo -I/opt/app/oracle/product/11.2.0/rdbms/public
-I/usr/include/python2.4 -c cx_Oracle.c -o build/temp.linux-x86_64-2.4-11g/cx_Oracle.o -DBUILD_VERSION=5.1.3

creating build/lib.linux-x86_64-2.4-11g

gcc -pthread -shared build/temp.linux-x86_64-2.4-11g/cx_Oracle.o -L/opt/app/oracle/product/11.2.0/lib -lclntsh -o build/lib.linux-x86_64-2.4-11g/cx_Oracle.so

[oracle@dg1 cx_Oracle-5.1.3]$ python setup.py install

running install

running build

running build_ext

running install_lib

copying build/lib.linux-x86_64-2.4-11g/cx_Oracle.so -> /usr/lib64/python2.4/site-packages

error: /usr/lib64/python2.4/site-packages/cx_Oracle.so: Permission denied

4.没有权限，换到ROOT用户再试。

[root@dg1 cx_Oracle-5.1.3]# python setup.py build

Traceback (most recent call last):

File "setup.py", line 135, in ?

raise DistutilsSetupError("cannot locate an Oracle software " \

distutils.errors.DistutilsSetupError: cannot locate an Oracle software installation

5.添加ORACLE 目录 设置后，再试

[root@dg1 cx_Oracle-5.1.3]# ORACLE_HOME=/opt/app/oracle/product/11.2.0; export ORACLE_HOME

[root@dg1 cx_Oracle-5.1.3]# echo $ORACLE_HOME

/opt/app/oracle/product/11.2.0

[root@dg1 cx_Oracle-5.1.3]# python setup.py build

running build

running build_ext

[root@dg1 cx_Oracle-5.1.3]# python setup.py install

running install

running build

running build_ext

running install_lib

copying build/lib.linux-x86_64-2.4-11g/cx_Oracle.so -> /usr/lib64/python2.4/site-packages

二、使用python 连接ORACLE 并导出查询数据

--------exp.py -----------------------------------------

import sys

import csv

import cx_Oracle

db=cx_Oracle.connect('tang','tang','192.168.2.100:1521/orcl')

#print db.version

printHeader= True

csv_file ="test.csv"

outputFile =open(csv_file,'w')

output = csv.writer(outputFile,dialect='excel')

sql='select * from (select email from user c where length(email)>3 ) '

curs = db.cursor()

curs.execute(sql)

if printHeader:

cols=[]

for col in curs.description:

cols.append(col[0])

output.writerow(cols)

for row_data in curs:

output.writerow(row_data)

outputFile.close()

db.close()

三、原使用 ORACLE dbms_output 包导出数据的方法：

------------exp.tst------------------

declare

P_FILENAME VARCHAR2(20);

v_value varchar2(800); --记录的数据

v_sql varchar2(4000);

v_fname varchar2(50);

type t_cursor is ref cursor ;

mycursor t_cursor;

outf utl_file.file_type;

begin

DBMS_OUTPUT.ENABLE(1000000); --加大缓存

v_fname:='test.csv';

v_sql:=

'select email from user c '||' where length(c.email)>3 )';

dbms_output.put_line(v_sql);

outf:=utl_file.fopen('DIR_ORACLE_USER',v_fname,'w');

open mycursor for v_sql;

loop

fetch mycursor into v_value;

exit when mycursor%notfound;

utl_file.put_line(outf,v_value);

end loop;

utl_file.fclose(outf);

end;