大约有 47,000 项符合查询结果（耗时：0.0568秒） [XML]
Is there any difference between GROUP BY and DISTINCT
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MusiGenesis' response is functionally the correct one with regard to your question as stated; the SQL Server is smart enough to realize that if you are using "Group By" and not using any aggregate functions, then what you actually mean is "Distinct" - and th...
What is “entropy and information gain”?
...: female
| | ends-vowel=0: male
length>=7
| length=5: male
basically each node represent a test performed on a single attribute, and we go left or right depending on the result of the test. We keep traversing the tree until we reach a leaf node which contains the class prediction (m or f)...
When should I use Struct vs. OpenStruct?
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@IvanKolmychek: Cool, actually I prefer the block approach.
– tokland
Mar 9 '16 at 18:21
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Handler vs AsyncTask vs Thread [closed]
...so supports reporting progress of the running tasks.
And a Thread is basically the core element of multithreading which a developer can use with the following disadvantage:
If you use Java threads you have to handle the following requirements
in your own code:
Synchronization with the...
ASP.NET MVC 404 Error Handling [duplicate]
... Nice! :) ErrorsController could inherit from the same base as all other controllers and thus have access to a certain functionality. Moreover, Error404 view could be wrapped in master providing the user with overall look and feel of the rest of the site without any extra work.
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How do I make a Git commit in the past?
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The advice you were given is flawed. Unconditionally setting GIT_AUTHOR_DATE in an --env-filter would rewrite the date of every commit. Also, it would be unusual to use git commit inside --index-filter.
You are dealing with multiple, independent problems here.
Specifying...
Using ping in c#
... InitializeComponent();
}
private void button1_Click(object sender, EventArgs e)
{
Ping p = new Ping();
PingReply r;
string s;
s = textBox1.Text;
r = p.Send(s);
i...
Get image data url in JavaScript?
...on. The images seem very similar/the same, still the Javascripted one is smaller and I'd love them to be exactly the same. One more thing: the input image is a small (594 bytes), 28x30 PNG with transparent background -- if that changes anything.
– Detariael
Ju...
How can I make a div stick to the top of the screen once it's been scrolled to?
... for. I'd like the element to start at 200px below the top of the page (to allow room for other content) and then once the user has scrolled down become fixed at the top.
– evanr
Aug 1 '09 at 8:10
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How to use QueryPerformanceCounter?
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#include <windows.h>
double PCFreq = 0.0;
__int64 CounterStart = 0;
void StartCounter()
{
LARGE_INTEGER li;
if(!QueryPerformanceFrequency(&li))
cout << "QueryPerformanceFrequency failed!\n";
PCFreq = double(li.QuadPart)/1000.0;
QueryP...