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what is the difference between GROUP BY and ORDER BY in sql
... returned.
GROUP BY will aggregate records by the specified columns which allows you to perform aggregation functions on non-grouped columns (such as SUM, COUNT, AVG, etc).
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How to select where ID in Array Rails ActiveRecord without exception
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If it is just avoiding the exception you are worried about, the "find_all_by.." family of functions works without throwing exceptions.
Comment.find_all_by_id([2, 3, 5])
will work even if some of the ids don't exist. This works in the
user.comments.find_all_by_id(potentially_nonexistent_id...
A more pretty/informative Var_dump alternative in PHP? [closed]
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A full year of time and labor after asking this, I've finally open sourced my version of var_dump, Kint. Read about it in the project page, or directly in github.
Here's a screenshot:
Sorry for the plug :)
EDIT: I'd just like to remind the commenters, that this is not a supp...
Why is there an “Authorization Code” flow in OAuth2 when “Implicit” flow works so well?
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tl;dr: This is all because of security reasons.
OAuth 2.0 wanted to meet these two criteria:
You want to allow developers to use non-HTTPS redirect URI because not all developers have an SSL enabled server and if they do it's not always ...
When would you use a WeakHashMap or a WeakReference?
...th user-supplied images, like the
web site design tool I work on.
Naturally you want to cache these
images, because loading them from disk
is very expensive and you want to
avoid the possibility of having two
copies of the (potentially gigantic)
image in memory at once.
Because an...
Does PHP have threading?
I found this PECL package called threads , but there is not a release yet. And nothing is coming up on the PHP website.
13...
Is there a performance impact when calling ToList()?
...on) constructor. This constructor must make a copy of the array (more generally IEnumerable<T>), otherwise future modifications of the original array will change on the source T[] also which wouldn't be desirable generally.
I would like to reiterate this will only make a difference with a hu...
How can I disable a button in a jQuery dialog from a function?
...tinue" button. I would like this "continue" button to only be enabled once all the fields have content in them, else it will remain disabled.
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Parse string to DateTime in C#
...teTime.Parse() will try figure out the format of the given date, and it usually does a good job. If you can guarantee dates will always be in a given format then you can use ParseExact():
string s = "2011-03-21 13:26";
DateTime dt =
DateTime.ParseExact(s, "yyyy-MM-dd HH:mm", CultureInfo.Invar...
How do you clone an Array of Objects in Javascript?
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The issue with your shallow copy is that all the objects aren't cloned. While the references to each object are unique in each array, once you ultimately grab onto it you're dealing with the same object as before. There is nothing wrong with the...