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Difference between EXISTS and IN in SQL?
...turns purely Boolean values, which is always faster than having to compare strings or values larger than a BIT/Boolean type. IN may or may not be a Boolean comparison. Since programming prefers EXPLICIT usage for stability (part of ACID), EXISTS is preferred generally.
– clift...
Name node is in safe mode. Not able to leave
...e leave
hadoop dfsadmin has been deprecated and so is hadoop fs command, all hdfs related tasks are being moved to a separate command hdfs.
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What is an MvcHtmlString and when should I use it?
The documentation for MvcHtmlString is not terribly enlightening:
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Making a WinForms TextBox behave like your browser's address bar
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First of all, thanks for answers! 9 total answers. Thank you.
Bad news: all of the answers had some quirks or didn't work quite right (or at all). I've added a comment to each of your posts.
Good news: I've found a way to make it wo...
How do I import CSV file into a MySQL table?
... MySQL table so that I can refactor into a sane format. I created a table called 'CSVImport' that has one field for every column of the CSV file. The CSV contains 99 columns , so this was a hard enough task in itself:
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Chrome Dev Tools: How to trace network for a link that opens a new tab?
...e://net-export in the latest version of Chrome) for a detailed overview of all network events happening in your browser.
Other possible solution, depending on your specific problem, may be to enable 'Preserve log' on the 'Network' tab:
and force all links to open in the same tab by executing ...
Autoreload of modules in IPython [duplicate]
Is there a way to have IPython automatically reload all changed code? Either before each line is executed in the shell or failing that when it is specifically requested to. I'm doing a lot of exploratory programming using IPython and SciPy and it's quite a pain to have to manually reload each module...
Create an empty list in python with certain size
...st comprehension (Using the squares because for range you don't need to do all this, you can just return range(0,9) ):
>>> def display():
... return [x**2 for x in range(9)]
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>>> print display()
[0, 1, 4, 9, 16, 25, 36, 49, 64]
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How to pull a random record using Django's ORM?
...['count']
random_index = randint(0, count - 1)
return self.all()[random_index]
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Coalesce function for PHP?
...HP 7 introduced a real coalesce operator:
echo $_GET['doesNotExist'] ?? 'fallback'; // prints 'fallback'
If the value before the ?? does not exists or is null the value after the ?? is taken.
The improvement over the mentioned ?: operator is, that the ?? also handles undefined variables without...