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Does a foreign key automatically create an index?
... I'm just about positive that PostgreSQL creates an index. I'm pretty sure MySQL does. Making the index makes a ton of sense, but IT'T NOT REQUIRED. After all, why reference something if every time the DB goes to look it up it has to do a tablescan?
– MBCook
Ma...
兼容主流浏览器的JS复制内容到剪贴板 - 更多技术 - 清泛网 - 专注C/C++及内核技术
...f文件进行真实的操作，因此这个方法也就失效了。
那么如何解决这个“真实操作”的问题呢？可以使用一个JavaScript库：Zero Clipboard，利用这个js库可以支持利用flash 10 实现复制到剪贴板。这个方法原理是在一个透明的flash（对...
App restarts rather than resumes
...l Activity. If those two flags are present and the Activity is not at the root of the task (meaning the app was already running), then I call finish() on the initial Activity. That exact solution may not work for you, but something similar should.
Here is what I do in onCreate() of the initial/l...
Favorite Django Tips & Features?
...ttings.py
import os
PROJECT_DIR = os.path.dirname(__file__)
...
STATIC_DOC_ROOT = os.path.join(PROJECT_DIR, "static")
...
TEMPLATE_DIRS = (
os.path.join(PROJECT_DIR, "templates"),
)
Credits: I got this tip from the screencast 'Django From the Ground Up'.
...
Is there a way to change the environment variables of another process in Unix?
...
Substantially, no. If you had sufficient privileges (root, or thereabouts) and poked around /dev/kmem (kernel memory), and you made changes to the process's environment, and if the process actually re-referenced the environment variable afterwards (that is, the process had not ...
Converting string to Date and DateTime
...
Like we have date "07/May/2018" and we need date "2018-05-07" as mysql compatible
if (!empty($date)) {
$timestamp = strtotime($date);
if ($timestamp === FALSE) {
$timestamp = strtotime(str_replace('/', '-', $date));
}
$date = date('Y-m-d', $timestamp);
...
scp (secure copy) to ec2 instance without password
... arguments in the wrong order. This works:
scp -i mykey.pem somefile.txt root@my.ec2.id.amazonaws.com:/
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Win32汇编--使用MASM - C/C++ - 清泛网 - 专注C/C++及内核技术
... invoke Sub3,1,2
编译后再进行反汇编，看编译器是如何转换处理不同类型的子程序的：
;这里是Sub1 – C类型
:00401000 55 push ebp
:00401001 8BEC mov ebp,esp
:00401003 8B4508 ...
How do I force git to use LF instead of CR+LF under windows?
... want git to normalize all the files in the repo. To do this, go to to the root of your repo and run these commands:
git rm --cached -rf .
git diff --cached --name-only -z | xargs -n 50 -0 git add -f
If you now want git to also normalize the files in your working directory, run these commands:
g...
django urls without a trailing slash do not redirect
...IA_URL.lstrip('/'),
'django.views.static.serve',
kwargs={'document_root': settings.MEDIA_ROOT}),
MEDIA_URL was empty, so this pattern matched everything.
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