大约有 44,000 项符合查询结果（耗时：0.0632秒） [XML]
MongoDB: Combine data from multiple collections into one..how?
...s). You need to have some key in both collections that you can use as an _id.
For example, let's say you have a users collection and a comments collection and you want to have a new collection that has some user demographic info for each comment.
Let's say the users collection has the following f...
Is there a `pointer-events:hoverOnly` or similar in CSS?
... it's easy enough to do in JQuery. Here's how I've done it:
HTML
<div
id="toplayer"
class="layer"
style="
z-index: 20;
pointer-events: none;
background-color: white;
display: none;
"
>
Top layer
</div>
<div id="bottomlayer" class="layer" style="z-index: 10"&g...
How do I use the conditional operator (? :) in Ruby?
...some extra junk after it), but they are not required in the last case as said issue does not arise.
You can use the "long-if" form for readability on multiple lines:
question = if question.size > 20 then
question.slice(0, 20) + "..."
else
question
end
...
What is a 'multi-part identifier' and why can't it be bound?
...
A multipart identifier is any description of a field or table that contains multiple parts - for instance MyTable.SomeRow - if it can't be bound that means there's something wrong with it - either you've got a simple typo, or a confusion...
Is it possible to start a shell session in a running container (without ssh)
...
EDIT: Now you can use docker exec -it "id of running container" bash (doc)
Previously, the answer to this question was:
If you really must and you are in a debug environment, you can do this: sudo lxc-attach -n <ID>
Note that the id needs to be the full on...
Caching a jquery ajax response in javascript/browser
...orks with GET and HEAD request.
You could roll your own solution as you said with something along these lines :
var localCache = {
data: {},
remove: function (url) {
delete localCache.data[url];
},
exist: function (url) {
return localCache.data.hasOwnProperty(url) &...
Best design for a changelog / auditing database table? [closed]
...rted from the very minimalistic design, like the one you described:
event ID
event date/time
event type
user ID
description
The idea was the same: to keep things simple.
However, it quickly became obvious that this minimalistic design was not sufficient. The typical audit was boiling down to qu...
JPA: How to have one-to-many relation of the same Entity type
...
Yes, this is possible. This is a special case of the standard bidirectional @ManyToOne/@OneToMany relationship. It is special because the entity on each end of the relationship is the same. The general case is detailed in Section 2.10.2 of the JPA 2.0 spec.
Here's a worked example. F...
HTML.ActionLink vs Url.Action in ASP.NET Razor
...mple:
@Html.ActionLink("link text", "someaction", "somecontroller", new { id = "123" }, null)
generates:
<a href="/somecontroller/someaction/123">link text</a>
and Url.Action("someaction", "somecontroller", new { id = "123" }) generates:
/somecontroller/someaction/123
There is a...
Is there a command to list all Unix group names? [closed]
...
Yes MichaelIT is right the groups command did not list all groups. I asked this because unsure if there is a simple command like groups to lists all groups names or even a swith to it like groups [-a|--all] to list all system groups without doing file scan.
...