大约有 45,000 项符合查询结果（耗时：0.0476秒） [XML]
Get top n records for each group of grouped results
...
Here is one way to do this, using UNION ALL (See SQL Fiddle with Demo). This works with two groups, if you have more than two groups, then you would need to specify the group number and add queries for each group:
(
select *
from mytable
where `group` = 1
order by age desc
...
Wait until all jQuery Ajax requests are done?
How do I make a function wait until all jQuery Ajax requests are done inside another function?
20 Answers
...
How can I make console.log show the current state of an object?
In Safari with no add-ons (and actually most other browsers), console.log will show the object at the last state of execution, not at the state when console.log was called.
...
View markdown files offline [closed]
Is there a way to display .md files offline so we know what it will look like once it's uploaded in Github? I'm referring to showing the README.md file as it would come out in Github, and not as for editing purposes.
...
HTML encoding issues - “” character showing up instead of “ ”
... legacy app just starting to misbehave, for whatever reason I'm not sure. It generates a bunch of HTML that gets turned into PDF reports by ActivePDF.
...
What's the point of malloc(0)?
...
According to the specifications, malloc(0) will return either "a null pointer or a unique pointer that can be successfully passed to free()".
This basically lets you allocate nothing, but still pass the "artist" variable to a call to free() without worry. For practical purposes,...
What is the Difference Between Mercurial and Git?
I've been using git for some time now on Windows (with msysGit) and I like the idea of distributed source control. Just recently I've been looking at Mercurial (hg) and it looks interesting. However, I can't wrap my head around the differences between hg and git.
...
Why should I not wrap every block in “try”-“catch”?
...ave always been of the belief that if a method can throw an exception then it is reckless not to protect this call with a meaningful try block.
...
Checkout one file from Subversion
"It is not possible to check out a single file. The finest level of checkouts you can do is at the directory level."
19 Ans...
Safely override C++ virtual functions
I have a base class with a virtual function and I want to override that function in a derived class. Is there some way to make the compiler check if the function I declared in the derived class actually overrides a function in the base class? I would like to add some macro or something that ensures ...