大约有 40,000 项符合查询结果（耗时：0.0750秒） [XML]
must appear in the GROUP BY clause or be used in an aggregate function
I have a table that looks like this caller 'makerar'
7 Answers
7
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Practical uses for AtomicInteger
I sort of understand that AtomicInteger and other Atomic variables allow concurrent accesses. In what cases is this class typically used though?
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When to use a View instead of a Table?
When should a View actually be used over an actual Table? What gains should I expect this to produce?
8 Answers
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Are inline virtual functions really a non-sense?
... excerpt from the excellent C++ faq:
"The only time an inline virtual call
can be inlined is when the compiler
knows the "exact class" of the object
which is the target of the virtual
function call. This can happen only
when the compiler has an actual object
rather than a pointer or ...
What is the optimal length for user password salt? [closed]
Any salt at all will obviously help when salting and hashing a user's password. Are there any best practices for how long the salt should be? I'll be storing the salt in my user table, so I would like the best tradeoff between storage size and security. Is a random 10 character salt enough? Or ...
X-UA-Compatible is set to IE=edge, but it still doesn't stop Compatibility Mode
...in the <head> element. No other meta tags, css links and js scripts calls can be placed before it.
<head>
<title>Site Title</title>
<meta http-equiv="X-UA-Compatible" content="IE=edge,chrome=1">
<meta charset="utf-8">
<script type="text/javascri...
Differences between unique_ptr and shared_ptr [duplicate]
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Both of these classes are smart pointers, which means that they automatically (in most cases) will deallocate the object that they point at when that object can no longer be referenced. The difference between the two is how many different pointers of each type can refer to a resource.
When using...
Should I use SVN or Git? [closed]
...r. It's decentralised to a point where people can track their own edits locally without having to push things to an external server.
SVN is designed to be more central where Git is based on each user having their own Git repo and those repos push changes back up into a central one. For that reason,...
What is the proper way to use the node.js postgresql module?
...ottleknecked based on how fast postgres
can respond to queries. It literally will line everything up, queuing
each query. Yeah, it's async and so that's alright...but wouldn't you
rather multiply your throughput by 10x? Use pg.connect set the
pg.defaults.poolSize to something sane (we do...
How to clear the canvas for redrawing
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A totally minor suggesting but I'd suggest context.clearRect(0, 0, context.canvas.width, context.canvas.height). It's effectively the same thing but one less dependency (1 variable instead of 2)
– gman
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