安装dmPython

一、安装dmPython

对于达梦数据库，必须首先安装dmPython，才可以使用，在$DM_HOME/drivers 目录下有多种类型的驱动：

[dmdba@dm8 ~]$ cd /dm/dmdbms/drivers/
[dmdba@dm8 drivers]$ ls
dci  dotNet  dpi  fldr  go  jdbc  logmnr  msgparse  odbc  php_pdo  python  r2dbc


[dmdba@dm8 drivers]$ cd python/
[dmdba@dm8 python]$ ls
django_dmPython2.0.0  django_dmPython3.0.0  dmPython  sqlalchemy  sqlalchemy1.4.6  sqlalchemy2.0.0

[dmdba@dm8 python]$ cd dmPython/
[dmdba@dm8 dmPython]$ ls
Buffer.c  Connection.c  Environment.c  Error.h    exLob.c     py_Dameng.c  README.txt  row.h     strct.h    trc.c  var.c      vBfile.c   vDateTime.c  vLob.c   vNumber.c  vString.c  Buffer.h  Cursor.c      Error.c        exBfile.c  exObject.c  py_Dameng.h  row.c       setup.py  tObject.c  trc.h  var_pub.h  vCursor.c  vInterval.c  vlong.c  vObject.c

这里我们需要手工安装dmPython 包。进入dmPython目录后执行命令：

python setup.py install

命令虽简单，但过程插曲比较多。

1、插曲一：权限问题Permission denied

开始使用dmdba 用户执行，报如下错误：

[dmdba@dm8 dmPython]$ python setup.py install
running install
error: can't create or remove files in install directory

[dmdba@dm8 dmPython]$ su
# 输入root密码
[root@dm8 ~]# 

2、 插曲二: cannot locate an Dameng software installation

切换成root用户执行，又报如下错误：

[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 <module>
    raise DistutilsSetupError("cannot locate an Dameng software " /
distutils.errors.DistutilsSetupError: cannot locate an Dameng software installation
[root@dm8 dmPython]#

因为安装依赖DM的环境，这里在root用户下配置dm的环境变量

[root@dm8 dmPython]# cat ~/.bash_profile
# .bash_profile
 
# Get the aliases and functions
if [ -f ~/.bashrc ]; then
    . ~/.bashrc
fi
 
# User specific environment and startup programs
 
PATH=$PATH:$HOME/bin
 
export PATH
export PATH="/dm/dmdbms/bin:$PATH"
export DM_HOME="/dm/dmdbms"
export LD_LIBRARY_PATH="$LD_LIBRARY_PATH:/dm/dmdbms/bin"

[root@dm8 dmPython]# source ~/.bash_profile

3 、插曲三：unable to execute gcc: No such file or directory

解决上面的问题后继续安装：

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

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]#


# 提示缺少gcc 包，直接yum 安装：

[root@dm8 dmPython]# yum install gcc* -y

4、插曲四：py_Dameng.h:8:20: fatal error: Python.h: No such file or directory

解决gcc 包之后继续安装：

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

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]#

# 这里是缺少python-devel 包，老方法，直接yum 解决：

[root@dm8 dmPython]# yum install python-devel

最后终于安装成功：

[root@dm8 dmPython]# python setup.py install
……
creating dist
creating 'dist/dmPython-2.3-py2.7-linux-x86_64.egg' and adding 'build/bdist.linux-x86_64/egg' to it
removing 'build/bdist.linux-x86_64/egg' (and everything under it)
Processing dmPython-2.3-py2.7-linux-x86_64.egg
Copying dmPython-2.3-py2.7-linux-x86_64.egg to /usr/lib64/python2.7/site-packages
Adding dmPython 2.3 to easy-install.pth file
 
Installed /usr/lib64/python2.7/site-packages/dmPython-2.3-py2.7-linux-x86_64.egg
Processing dependencies for dmPython==2.3
Finished processing dependencies for dmPython==2.3
[root@dm8 dmPython]#

二、测试dmPython

[root@dm8 dmPython]# python
Python 2.7.5 (default, Feb 20 2018, 09:19:12) 
[GCC 4.8.5 20150623 (Red Hat 4.8.5-28)] on linux2
Type "help", "copyright", "credits" or "license" for more information.

# 测试代码（更换成自己的达梦配置）
>>> 
import dmPython
conn=dmPython.connect(user='SYSDBA',password='SYSDBA',server= '192.168.201.118',port=5236)
cursor = conn.cursor()
cursor.execute('select username from dba_users')
values = cursor.fetchall()
print(values)
cursor.close()
conn.close()

输出数据库中的用户名则表示连接数据库成功。

https://eco.dameng.com/document/dm/zh-cn/start/python-development.html