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Error 1022 - Can't write; duplicate key in table
...ou can not have the same foreign key names in the database tables.
Check all your tables and all your foreign keys and avoid having two foreign keys with the same exact name.
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What does the “===” operator do in Ruby? [duplicate]
...
Just like with every other method in Ruby (or actually pretty much any object-oriented language),
a === b
means whatever the author of a's class wants it to mean.
However, if you don't want to confuse the heck out of your colleagues, the convention is that === is the cas...
How can I parse JSON with C#?
... @Fil That gives you a value of type object, and you can't use indexing on a object.
– Alex
Jul 18 '17 at 8:15
...
Django DB Settings 'Improperly Configured' Error
...--settings=mysite.settings (or whatever settings module you use)
Set DJANGO_SETTINGS_MODULE environment variable in your OS to mysite.settings
(This is removed in Django 1.6) Use setup_environ in the python interpreter:
from django.core.management import setup_environ
from mysite import settings
s...
How can I listen for a click-and-hold in jQuery?
...tartTrigger(e) {
var $elem = $(this);
$elem.data('mouseheld_timeout', setTimeout(function() {
$elem.trigger('mouseheld');
}, e.data));
}
function stopTrigger() {
var $elem = $(this);
clearTimeout($elem.data('mouseheld_timeout'));
}
...
“x not in y” or “not x in y”
...am' not in 'spam and eggs'
>>> dis.dis(notin)
2 0 LOAD_CONST 1 ('ham')
3 LOAD_CONST 2 ('spam and eggs')
6 COMPARE_OP 7 (not in)
9 POP_TOP
10 LOAD_CONST 0 (...
MongoDB副本集详解 优于以往的主从模式 - 大数据 & AI - 清泛网 - 专注C/C++及内核技术
...ngodb.org/downloads
实验环境使用的Mongodb版本为mongodb-linux-x86_64-2.6.0
由三台虚拟机搭建，配置为单核,1G内存。实验环境如下:
MongoDB的副本集不同于以往的主从模式。
在集群Master故障的时候，副本集可以自动投票，选举出新的Maste...
How to ignore deprecation warnings in Python
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This doesn't work for me at all, still seeing deprecationwarnings.
– user1244215
Oct 22 '13 at 0:43
9
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How to use a servlet filter in Java to change an incoming servlet request url?
... a check in the code if the URL needs to be changed and if not, then just call FilterChain#doFilter(), else it will call itself in an infinite loop.
Alternatively you can also just use an existing 3rd party API to do all the work for you, such as Tuckey's UrlRewriteFilter which can be configured th...
How to run a python script from IDLE interactive shell?
...s.call(['python', 'helloworld.py']) # Just run the program
subprocess.check_output(['python', 'helloworld.py']) # Also gets you the stdout
With arguments:
subprocess.call(['python', 'helloworld.py', 'arg'])
Read the docs for details :-)
Tested with this basic helloworld.py:
import sys
if le...