摘要：记录在 Linux 环境下使用 DM 的 python 驱动实现数据库 CRUD 操作，包括驱动安装中的报错内容。
安装Python

Linux 环境一般自带 Python，查看 Python 版本：
[root@localhost ~]# python
Python 2.7.5 (default, Nov 16 2020, 22:23:17)
[GCC 4.8.5 20150623 (Red Hat 4.8.5-44)] on linux2
Type "help", "copyright", "credits" or "license" for more information.

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在 DM 的 Python 驱动包下有 README.TXT 文件，此处记录按照此文件说明的安装步骤操作。
添加环境变量

README.TXT 内容：
=安装===

dmPython源码依赖DM安装目录中提供的include头文件，安装前需要检查环境中是否存在DM安装，并设置DM_HOME目录：

export DM_HOME=/opt/dmdbms

具体路径以实际环境为准，DM_HOME路径下面必须有include目录

在Windows操作系统下安装dmPython只需要直接执行exe文件即可。Windows操作系统下生成exe文件操作如下：

1.进入到dmPython源码所在目录（setup.py文件所在路径）

2.执行命令：python setup.py bdist_wininst

3.在dist目录下会生成相关安装文件

LINUX安装方法：

1.进入到dmPython源码所在目录（setup.py文件所在路径）

2.执行命令：python setup.py bdist_rpm

3.在dist目录下会生成相关rpm包

4.在Linux操作系统下使用rpm包安装dmPython。安装和卸载命令参考如下：

安装：rpm -ivh dmPython-2.1-7.1-py33-1.x86_64.rpm --nodeps

卸载：rpm -e dmPython-2.1-1.x86_64

windows和linux也可以直接使用源码安装，操作如下：

1.进入到dmPython源码所在目录（setup.py文件所在路径）

2.执行命令：python setup.py install
Markdown

修改 /etc/profile 文件，添加 DM 数据库环境变量：
export PATH="/opt/dmdbms/bin:$PATH"

export LD_LIBRARY_PATH="$LD_LIBRARY_PATH:/opt/dmdbms/bin"

export DM_HOME=/opt/dmdbms

检查：

[root@localhost dmPython]# echo $DM_HOME

/opt/dmdbms
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编译安装

进入 Python 驱动目录，执行 python setup.py bdist_rpm ，此命令会在 ./dist 目录下生成 rpm 包。
安装中遇到的报错如下：
报错一：
[dmdba@dm8 dmPython]$ python setup.py install

running install

error: can't create or remove files in install directory

The following error occurred while trying to add or remove files in the

installation directory:

[Errno 13] Permission denied: '/usr/lib64/python2.7/site-packages/test-easy-install-3032.write-test'

The installation directory you specified (via --install-dir, --prefix, or

the distutils default setting) was:

/usr/lib64/python2.7/site-packages/

Perhaps your account does not have write access to this directory? If the

installation directory is a system-owned directory, you may need to sign in

as the administrator or "root" account. If you do not have administrative

access to this machine, you may wish to choose a different installation

directory, preferably one that is listed in your PYTHONPATH environment

variable.

For information on other options, you may wish to consult the

documentation at:

https://pythonhosted.org/setuptools/easy_install.html

Please make the appropriate changes for your system and try again.

[dmdba@dm8 dmPython]$

根据提示，需要使用root用户来安装dmPython。
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报错二：
[root@dm8 ~]# cd /dm/dmdbms/drivers/python/dmPython

[root@dm8 dmPython]# python setup.py install

Traceback (most recent call last):

File "setup.py", line 103, in

raise DistutilsSetupError("cannot locate an Dameng software " /

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

[root@dm8 dmPython]#
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需要配置环境变量
报错三：
[root@dm8 dmPython]# source ~/.bash_profile

[root@dm8 dmPython]# python setup.py install

running install

running bdist_egg

running egg_info

creating dmPython.egg-info

writing dmPython.egg-info/PKG-INFO

writing top-level names to dmPython.egg-info/top_level.txt

writing dependency_links to dmPython.egg-info/dependency_links.txt

writing manifest file 'dmPython.egg-info/SOURCES.txt'

reading manifest file 'dmPython.egg-info/SOURCES.txt'

writing manifest file 'dmPython.egg-info/SOURCES.txt'

installing library code to build/bdist.linux-x86_64/egg

running install_lib

running build_ext

building 'dmPython' extension

creating build

creating build/temp.linux-x86_64-2.7

gcc -pthread -fno-strict-aliasing -O2 -g -pipe -Wall -Wp,-D_FORTIFY_SOURCE=2 -fexceptions -fstack-protector-strong --param=ssp-buffer-size=4 -grecord-gcc-switches -m64 -mtune=generic -D_GNU_SOURCE -fPIC -fwrapv -DNDEBUG -O2 -g -pipe -Wall -Wp,-D_FORTIFY_SOURCE=2 -fexceptions -fstack-protector-strong --param=ssp-buffer-size=4 -grecord-gcc-switches -m64 -mtune=generic -D_GNU_SOURCE -fPIC -fwrapv -fPIC -DDM64 -I/dm/dmdbms/include -I/usr/include/python2.7 -c py_Dameng.c -o build/temp.linux-x86_64-2.7/py_Dameng.o -DBUILD_VERSION=2.3

unable to execute gcc: No such file or directory

error: command 'gcc' failed with exit status 1

[root@dm8 dmPython]#
Bash

提示缺少gcc 包，直接yum 安装：yum -y install gcc*
报错四：
[root@dm8 dmPython]# python setup.py install

running install

running bdist_egg

running egg_info

writing dmPython.egg-info/PKG-INFO

writing top-level names to dmPython.egg-info/top_level.txt

writing dependency_links to dmPython.egg-info/dependency_links.txt

reading manifest file 'dmPython.egg-info/SOURCES.txt'

writing manifest file 'dmPython.egg-info/SOURCES.txt'

installing library code to build/bdist.linux-x86_64/egg

running install_lib

running build_ext

building 'dmPython' extension

gcc -pthread -fno-strict-aliasing -O2 -g -pipe -Wall -Wp,-D_FORTIFY_SOURCE=2 -fexceptions -fstack-protector-strong --param=ssp-buffer-size=4 -grecord-gcc-switches -m64 -mtune=generic -D_GNU_SOURCE -fPIC -fwrapv -DNDEBUG -O2 -g -pipe -Wall -Wp,-D_FORTIFY_SOURCE=2 -fexceptions -fstack-protector-strong --param=ssp-buffer-size=4 -grecord-gcc-switches -m64 -mtune=generic -D_GNU_SOURCE -fPIC -fwrapv -fPIC -DDM64 -I/dm/dmdbms/include -I/usr/include/python2.7 -c py_Dameng.c -o build/temp.linux-x86_64-2.7/py_Dameng.o -DBUILD_VERSION=2.3

In file included from py_Dameng.c:3:0:

py_Dameng.h:8:20: fatal error: Python.h: No such file or directory

#include <Python.h>

^

compilation terminated.

error: command 'gcc' failed with exit status 1

[root@dm8 dmPython]#
Bash

提示：py_Dameng.h:8:20: fatal error: Python.h: No such file or directory 是缺少 python-devel 包，直接yum 安装 yum install python-devel -y
报错五：如提示 fatal error: py_Dameng.h(Error.h): No such file or directory 可将驱动目录下所有文件复制到 dmdbms/include 目录。
报错六：如在 import dmPython 时提示 libcrypto.so not found等类似错误，可在存有此文件的目录下执行 python ，此文件一般在 dmdbms/bin 下。
至此，安装成功。
创建测试表
创建测试表并插入数据，本例中使用本地数据库，端口 5236，用户/口令：SYSDBA/SYSDBA 。
create table SYSDBA.TEST(id int, name varchar);
insert into SYSDBA.TEST(id,name) values(1,'qian'),(2,'sun'),(3,'tian');
commit;
SQL

测试表创建完成后，可以测试 python 连接：
[root@localhost bin]# python

Python 2.7.5 (default, Nov 16 2020, 22:23:17)

[GCC 4.8.5 20150623 (Red Hat 4.8.5-44)] on linux2

Type "help", "copyright", "credits" or "license" for more information.

import dmPython

conn=dmPython.connect(user='SYSDBA',password='SYSDBA',server='localhost',port=5236)

cursor=conn.cursor()

cursor.execute("select *from SYSDBA.TEST")

<builtin.DmdbCursor on <dmPython.Connection to SYSDBA@localhost:5236>>

results = cursor.fetchall()

results

[(1L, 'qian'), (2L, 'sun'), (3L, 'tian')]

cursor.close()

conn.close()

或

[root@localhost bin]# python

Python 2.7.5 (default, Nov 16 2020, 22:23:17)

[GCC 4.8.5 20150623 (Red Hat 4.8.5-44)] on linux2

Type "help", "copyright", "credits" or "license" for more information.

import dmPython

conn=dmPython.connect(user='SYSDBA',password='SYSDBA',server='localhost',port=5236)

print(conn)

<dmPython.Connection to SYSDBA@localhost:5236>

Bash

数据库连接成功
编写测试代码

创建文件 dm_python.py 并编码。其中包含六个方法，分别为主测试方法（main），连接获取方法（getConnection），查询方法（select_data），新增方法（insert_data），修改方法（update_data），删除方法（delete_data）；
dm_python.py

-- coding: utf-8 --

import dmPython

username = "SYSDBA"
passwd = "SYSDBA"
server_name = "localhost"
server_port = 5236

#获取数据库连接
def getConnection():
conn = dmPython.connect(user=username,password=passwd,server=server_name,port=server_port)
return conn

#新增方法
def insert_data():
connection = getConnection()
userid = raw_input('请输入ID：')
name = raw_input('请输入姓名：')

try:
    query = "insert into test(id,name) values(?,?)"
    cursor = connection.cursor()

    cursor.execute(query,[userid,name])

    connection.commit()
    print("数据保存成功！")

except:
    print("啊哦，出现了一些错误~")

finally:
    connection.close()
return

#查询方法
def select_data():

connection = getConnection()
cursor = connection.cursor()
cursor.execute('select *from SYSDBA.TEST')

for row in cursor:
    print ('Records = %r' % (row,))
return

#更新方法
def update_data():

connection = getConnection()
userid = raw_input('请输入要更新的记录ID：')

try:
    sql = "select *from SYSDBA.TEST where id = ?"
    cursor = connection.cursor()
    cursor.execute(sql,[userid])
    item = cursor.fetchone()
    user_str = "即将更新的数据 ID 为：" + userid

    print(user_str)
    print("ID\t\t Name")
    print('-----------------------------')
    print('{}\t\t {}'.format(item[0],item[1]))
    print('请输入新的Name字段值')

    name = raw_input('新的名称：')
    query = "update test set name = ? where id = ?"

    cursor.execute(query,[name,userid])
    connection.commit()
    print('数据更新成功！')

except:
    print('啊哦，更新失败了~')

finally:
    connection.close()
return

#删除方法
def delete_data():

connection = getConnection()
userid = raw_input('请输入要删除的记录ID：')

try:
    sql = "select *from SYSDBA.TEST where id = ?"
    cursor = connection.cursor()
    cursor.execute(sql,[userid])
    item = cursor.fetchone()
    user_str = "即将删除的数据 ID 为：" + userid

    print(user_str)
    print("ID\t\t Name")
    print('-----------------------------')
    print('{}\t\t {}'.format(item[0],item[1]))



    confirm = raw_input('你确定要删除这条记录吗？（Y/N）')
    if confirm == 'Y':
        query = "delete from SYSDBA.TEST where id = ?"
        cursor.execute(query,[userid])
        connection.commit()
        print('数据删除成功！')
    else:
        print('数据删除失败！')

except:
    print('啊哦，删除失败了~')

finally:
    connection.close()
return

#主测试函数
def main():
print('请输入当前要操作的类型：N=新增，R=查询，U=更新，D=删除')
choice = raw_input('您的选项是：')

if choice == 'N':
    insert_data()
elif choice == 'R':
    select_data()
elif choice == 'U':
    update_data()
elif choice == 'D':
    delete_data()
else:
    print('住手！我看你有奇怪的想法。')
return

main()
Python

测试

对上面文件中编写的方法进行测试。
[root@localhost bin]# python dm_python.py

请输入当前要操作的类型：N=新增，R=查询，U=更新，D=删除

您的选项是：N

请输入ID：4

请输入姓名：zhou

数据保存成功！

[root@localhost bin]# python dm_python.py

请输入当前要操作的类型：N=新增，R=查询，U=更新，D=删除

您的选项是：R

Records = (1L, 'qian')

Records = (2L, 'sun')

Records = (3L, 'tian')

Records = (4L, 'zhou')

[root@localhost bin]# python dm_python.py

请输入当前要操作的类型：N=新增，R=查询，U=更新，D=删除

您的选项是：U

请输入要更新的记录ID：4

即将更新的数据 ID 为：4

ID Name

---

4 zhou

请输入新的Name字段值

新的名称：zhou_new

数据更新成功！

[root@localhost bin]# python dm_python.py

请输入当前要操作的类型：N=新增，R=查询，U=更新，D=删除

您的选项是：R

Records = (1L, 'qian')

Records = (2L, 'sun')

Records = (3L, 'tian')

Records = (4L, 'zhou_new')

[root@localhost bin]# python dm_python.py

请输入当前要操作的类型：N=新增，R=查询，U=更新，D=删除

您的选项是：D

请输入要删除的记录ID：4

即将删除的数据 ID 为：4

ID Name

---

4 zhou_new

你确定要删除这条记录吗？（Y/N）Y

数据删除成功！

[root@localhost bin]# python dm_python.py

请输入当前要操作的类型：N=新增，R=查询，U=更新，D=删除

您的选项是：R

Records = (1L, 'qian')

Records = (2L, 'sun')

Records = (3L, 'tian')

create table SYSDBA.TEST(id int, name varchar);
insert into SYSDBA.TEST(id,name) values(1,'qian'),(2,'sun'),(3,'tian');
commit;

create table SYSDBA.TEST(id int, name varchar);
insert into SYSDBA.TEST(id,name) values(1,'qian'),(2,'sun'),(3,'tian');
commit;

[root@localhost ~]# python

Python 2.7.5 (default, Nov 16 2020, 22:23:17)

[GCC 4.8.5 20150623 (Red Hat 4.8.5-44)] on linux2

Type "help", "copyright", "credits" or "license" for more information.

Bash