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Possibility of duplicate Mongo ObjectId's being generated in two different collections?
... }
> db.foo.insert({_id: 'abc', data:'xyz'})
E11000 duplicate key error index: test.foo.$_id_ dup key: { : "abc" }
So, absolutely don't rely on _id's being unique across collections, and since you don't control the ObjectId generation function, don't rely on it.
It's possible to create somet...
MVC 3: How to render a view without its layout page when loaded via ajax?
...ws/Shared/_Layout.cshtml";
}
and in the controller:
public ActionResult Index()
{
return View();
}
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Best way to select random rows PostgreSQL
... few) gaps.
Obviously no or few write operations.
Your ID column has to be indexed! A primary key serves nicely.
The query below does not need a sequential scan of the big table, only an index scan.
First, get estimates for the main query:
SELECT count(*) AS ct -- optional
, mi...
How to clear all the jobs from Sidekiq?
I am using sidekiq for background tasks in Rails application. Now the numbers of jobs becomes more, so I want to clear all the jobs. I tried the following command in console
...
How do I exit from the text window in Git?
...vim, you can press i to start entering text and save by pressing esc and :wq and enter, this will commit with the message you typed. In your current state, to just come out without committing, you can do :q instead of the :wq as mentioned above.
Alternatively, you can just do git commit -m '<mes...
Injecting $state (ui-router) into $http interceptor causes circular dependency
... get a reference to the $state service.
var interceptor = ['$location', '$q', '$injector', function($location, $q, $injector) {
function success(response) {
return response;
}
function error(response) {
if(response.status === 401) {
$injector.get('$state')....
How to write UPDATE SQL with Table alias in SQL Server 2008?
I have a very basic UPDATE SQL -
2 Answers
2
...
How do I print out the contents of an object in Rails for easy debugging?
...onView::Helpers::DebugHelper
#app/view/controllers/post_controller.rb
def index
@posts = Post.all
end
#app/view/posts/index.html.erb
<%= debug(@posts) %>
#start your server
rails -s
results (in browser)
- !ruby/object:Post
raw_attributes:
id: 2
title: My Second Post
body: ...
正则表达式 30 分钟入门教程 - 更多技术 - 清泛网 - 专注C/C++及内核技术
...输入的内容时非常有用，比如一个网站如果要求你填写的QQ号必须为5位到12位数字时，可以使用：^\d{5,12}$。
这里的{5,12}和前面介绍过的{2}是类似的，只不过{2}匹配只能不多不少重复2次，{5,12}则是重复的次数不能少于5次，不能...
select and update database record with a single queryset
How do I run an update and select statements on the same queryset rather than having to do two queries:
- one to select the object
- and one to update the object
...