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MySQL select 10 random rows from 600K rows fast
How can I best write a query that selects 10 rows randomly from a total of 600k?
26 Answers
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Can I bind an array to an IN() condition?
...right. fixed the code (didn't test it though)
edit: both chris (comments) and somebodyisintrouble suggested that the foreach-loop ...
(...)
// bindvalue is 1-indexed, so $k+1
foreach ($ids as $k => $id)
$stmt->bindValue(($k+1), $id);
$stmt->execute();
... might be redundant, so the...
Color different parts of a RichTextBox string
...ox.AppendText(text);
box.SelectionColor = box.ForeColor;
}
}
And this is how you would use it:
var userid = "USER0001";
var message = "Access denied";
var box = new RichTextBox
{
Dock = DockStyle.Fill,
Font = new Font("Courier New", 10...
Twitter Bootstrap 3: how to use media queries?
...ecause "extra small" is the default. I.e. you would first code the XS size and then have these media overrides afterwards.
@media(min-width:576px){}
@media(min-width:768px){}
@media(min-width:992px){}
@media(min-width:1200px){}
Update 2019-02-11: BS3 info is still accurate as of version 3.4.0, up...
Do try/catch blocks hurt performance when exceptions are not thrown?
...mployee we came across a large section of code inside a try{} block. She and an IT representative suggested this can have effects on performance of the code. In fact, they suggested most of the code should be outside of try/catch blocks, and that only important sections should be checked. The Micr...
Meaning of 'const' last in a function declaration of a class?
...method the this pointer will essentially become a pointer to const object, and you cannot therefore change any member data. (Unless you use mutable, more on that later).
The const keyword is part of the functions signature which means that you can implement two similar methods, one which is called ...
Pandas timeseries plot setting x-axis major and minor ticks and labels
I want to be able to set the major and minor xticks and their labels for a time series graph plotted from a Pandas time series object.
...
Best way to specify whitespace in a String.Split operation
... to be the delimiters. White-space characters are defined by the Unicode standard and return true if they are passed to the Char.IsWhiteSpace method.
Always, always, always read the documentation!
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Why are private fields private to the type, not the instance?
In C# (and many other languages) it's perfectly legitimate to access private fields of other instances of the same type. For example:
...
Change the Target Framework for all my projects in a Visual Studio Solution
...man's Visual Studio macro available on CodeProject:
Visual Studio 2010 and Target Framework Version
Below is the code, download it to your <UserProfile>\Documents\Visual Studio 2010\Projects\VSMacros80\MyMacros folder, open the Visual Studio Macro IDE (Alt-F11) and add it as an existing ...