一个 Django 的超简单的数据库应用
昨天 Launch & Learn 的时候，做了个简单的 Django 的数据库应用，以配合 Li Li Zhang 的 ORM Course。
其实用 Django 做数据库应用真的很简单，不过比较适合用于重头设计的 Database Schema，然后用 syncdb 来同步数据库。
目前 Django 对 ForeignKey 和 One to One, One to Many, Many to Many 支持得都不错，最大的缺陷还是缺乏 Join 的支持导致多表联查的性能不好，这也是我在做开发的过程中碰到的最大问题。
其实用 Django 重头做一个数据库开发非常简单，用下面几步就可以了。
FIRST: Create new project and a new app with django-admin.py $ django-admin.py startproject [project_name] $ cd [project_name] $ django-admin.py startapp [app_name] SECOND: Edit the settings.py file to adjust db settings and installed apps. THIRD: Edit the [app_name]/models.py to modeling the database schema FOURTH: Edit the [prject_name]/urls.py to adjust the path of URL. FIFTH: Edit the [app_name]/views.py to realize your function. SIXTH: To run the manage.py to start the test server in the project. $ ./manage.py runserver THE END: Use your browser to navigate to your http://localhost:8000 and enjoy in it. :-)
这里提供了一个范例，也是昨天在 Launch and Learn 上演示过的：www.box.net/shared/6036abumgv 中的 lnl.tar.bz2 文件，里面提供的 Steps 其实就是上面那段，只是代码中也提供了注释以方便阅读。
在 Mac OS X 上为 Django 安装 MySQL-python 1.2.2
在 Mac OS X 上安装 MySQL-python 花了一点点功夫, 记一下:
先去 Sun 网站上下载最新版本的 MySQL, 再去 djangoproject.org 上下载最新版本的 Django 1.0 release, 并且正常安装.
然后用 easyinstall mysql-python, 发现无法正常安装.
查看 easyinstall 的下载路径, 用下面的命令下载并且解压缩
然后修改 site.cfg, 修改下面内容:
由
改成
否则会出现找不到 MySQL config 的问题:
然后修改 _mysql.c, 把第 37 到 39 行注释掉, 如下:
否则会出现:
然后再用 python ./setup.py build 编译
然后再用 python ./setup.py install 安装
然后用下面的命令进行测试:
如果能正常输出就没有问题了 :-)
先去 Sun 网站上下载最新版本的 MySQL, 再去 djangoproject.org 上下载最新版本的 Django 1.0 release, 并且正常安装.
然后用 easyinstall mysql-python, 发现无法正常安装.
查看 easyinstall 的下载路径, 用下面的命令下载并且解压缩
$ cd /tmp $ curl -o MySQL-python-1.2.2.tar.gz http://internap.dl.sourceforge.net/sourceforge/mysql-python/MySQL-python-1.2.2.tar.gz $ tar xvf MySQL-python-1.2.2.tar.gz $ cd MySQL-python-1.2.2
然后修改 site.cfg, 修改下面内容:
由
#mysql_config = /usr/local/bin/mysql_config
改成
mysql_config = /usr/local/mysql/bin/mysql_config
否则会出现找不到 MySQL config 的问题:
... File "/tmp/easy_install-nHSsgl/MySQL-python-1.2.2/setup_posix.py", line 24, in mysql_config EnvironmentError: mysql_config not found
然后修改 _mysql.c, 把第 37 到 39 行注释掉, 如下:
//#ifndef uint //#define uint unsigned int //#endif
否则会出现:
In file included from /usr/local/mysql/include/mysql.h:47,
from _mysql.c:40:
/usr/include/sys/types.h:92: error: duplicate 'unsigned'
/usr/include/sys/types.h:92: error: two or more data types in declaration specifiers
error: command 'gcc' failed with exit status 1
然后再用 python ./setup.py build 编译
$ python ./setup.py build running build running build_py copying MySQLdb/release.py -> build/lib.macosx-10.5-i386-2.5/MySQLdb running build_ext building '_mysql' extension gcc -fno-strict-aliasing -Wno-long-double -no-cpp-precomp -mno-fused-madd -fno-common -dynamic -DNDEBUG -g -Os -Wall -Wstrict-prototypes -DMACOSX -I/usr/include/ffi -DENABLE_DTRACE -pipe -Dversion_info=(1,2,2,'final',0) -D__version__=1.2.2 -I/usr/local/mysql/include -I/System/Library/Frameworks/Python.framework/Versions/2.5/include/python2.5 -c _mysql.c -o build/temp.macosx-10.5-i386-2.5/_mysql.o -g -Os -arch i386 -fno-common -D_P1003_1B_VISIBLE -DSIGNAL_WITH_VIO_CLOSE -DSIGNALS_DONT_BREAK_READ -DIGNORE_SIGHUP_SIGQUIT gcc -Wl,-F. -bundle -undefined dynamic_lookup -arch i386 -arch ppc build/temp.macosx-10.5-i386-2.5/_mysql.o -L/usr/local/mysql/lib -lmysqlclient_r -lz -lm -lmygcc -o build/lib.macosx-10.5-i386-2.5/_mysql.so ld: warning in build/temp.macosx-10.5-i386-2.5/_mysql.o, file is not of required architecture ld: warning in /usr/local/mysql/lib/libmysqlclient_r.dylib, file is not of required architecture ld: warning in /usr/local/mysql/lib/libmygcc.a, file is not of required architecture
然后再用 python ./setup.py install 安装
$ sudo python ./setup.py install Password: running install running bdist_egg running egg_info writing MySQL_python.egg-info/PKG-INFO writing top-level names to MySQL_python.egg-info/top_level.txt writing dependency_links to MySQL_python.egg-info/dependency_links.txt reading manifest file 'MySQL_python.egg-info/SOURCES.txt' reading manifest template 'MANIFEST.in' writing manifest file 'MySQL_python.egg-info/SOURCES.txt' installing library code to build/bdist.macosx-10.5-i386/egg running install_lib running build_py copying MySQLdb/release.py -> build/lib.macosx-10.5-i386-2.5/MySQLdb running build_ext creating build/bdist.macosx-10.5-i386 creating build/bdist.macosx-10.5-i386/egg copying build/lib.macosx-10.5-i386-2.5/_mysql.so -> build/bdist.macosx-10.5-i386/egg copying build/lib.macosx-10.5-i386-2.5/_mysql_exceptions.py -> build/bdist.macosx-10.5-i386/egg creating build/bdist.macosx-10.5-i386/egg/MySQLdb ...
然后用下面的命令进行测试:
$ cd ~ $ python Python 2.5.1 (r251:54863, Apr 15 2008, 22:57:26) [GCC 4.0.1 (Apple Inc. build 5465)] on darwin Type "help", "copyright", "credits" or "license" for more information. >>> import MySQLdb >>> MySQLdb.apilevel '2.0' >>> import django >>> print django.VERSION (1, 0, 'final')
如果能正常输出就没有问题了 :-)
