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When to use EntityManager.find() vs EntityManager.getReference() with JPA
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I usually use getReference method when i do not need to access database state (I mean getter method). Just to change state (I mean setter method). As you should know, getReference returns a proxy object which uses a powerful featu...
How do you set, clear, and toggle a single bit?
... behaviour to shift by more than the width of a long. The same applies to all the rest of the examples.
Clearing a bit
Use the bitwise AND operator (&) to clear a bit.
number &= ~(1UL << n);
That will clear the nth bit of number. You must invert the bit string with the bitwise NOT op...
How to check if a user likes my Facebook Page or URL using Facebook's API
...xample, the act of liking a Page or checking in to a Place cannot automatically register or enter a promotion participant." - facebook.com/promotions_guidelines.php
– Chris Jacob
May 18 '11 at 1:25
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ERROR 2002 (HY000): Can't connect to local MySQL server through socket '/tmp/mysql.sock'
I installed MySQL on Mac OS X Mountain Lion with homebrew install mysql , but when I tried mysql -u root I got the following error:
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detect key press in python?
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Python has a keyboard module with many features. Install it, perhaps with this command:
pip3 install keyboard
Then use it in code like:
import keyboard # using module keyboard
while True: # making a loop
try: # used try so that if user pressed other than the given ...
JavaScript chop/slice/trim off last character in string
...viously using the substring version. Thanks!
– Matt Ball
Apr 13 '10 at 14:09
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forgive me if I'm...
Eclipse: Can you format code on save?
...checking your eclipse format xml descriptor into source control. That way all members of the team can use it and you don't get to and fro reformatting battles.
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Combine multiple Collections into a single logical Collection?
...llections (e.g. 3 ArrayLists) as members of a class. Now, I want to expose all the elements to other classes so they can simply iterate over all elements (ideally, read only).
I'm using guava collections and I wonder how I could use guava iterables/iterators to generate a logical view on the interna...
iOS 7's blurred overlay effect using CSS?
...s CSS Clip property
that's it.
I also believe this could be done dynamically for any screen if using canvas to copy the current dom and blurring it.
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data.table vs dplyr: can one do something well the other can't or does poorly?
...j and by together is by design. By keeping related operations together, it allows to easily optimise operations for speed and more importantly memory usage, and also provide some powerful features, all while maintaining the consistency in syntax.
1. Speed
Quite a few benchmarks (though mostly on g...