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Database Structure for Tree Data Structure
...o-nested-sets
There are other models as well, including materialized path and nested sets:
http://communities.bmc.com/communities/docs/DOC-9902
Joe Celko has written a book on this subject, which is a good reference from a general SQL perspective (it is mentioned in the nested set article link abo...
Usage of protocols as array types and function parameters in swift
.... Such protocols use Self or associatedtype keywords in their definitions (and Equatable is one of them).
In some cases it's possible to use a type-erased wrapper to make your collection homomorphic. Below is an example.
// This protocol doesn't provide polymorphism over the types which implement ...
Haskell error parse error on input `='
I'm new to Haskell and after starting ghci I tried:
4 Answers
4
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C++ catching all exceptions
...nt to add separate catch clauses for the various exceptions you can catch, and only catch everything at the bottom to record an unexpected exception. E.g.:
try{
// ...
} catch (const std::exception& ex) {
// ...
} catch (const std::string& ex) {
// ...
} catch (...) {
// .....
How to close a Java Swing application from the code
What is the proper way to terminate a Swing application from the code, and what are the pitfalls?
9 Answers
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Does MySQL ignore null values on unique constraints?
...sult:
x
NULL
NULL
1
This is not true for all databases. SQL Server 2005 and older, for example, only allows a single NULL value in a column that has a unique constraint.
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Scanner is skipping nextLine() after using next() or nextFoo()?
I am using the Scanner methods nextInt() and nextLine() for reading input.
19 Answers
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GCM with PHP (Google Cloud Messaging)
...tiple registration IDs via PHP CURL.
// Payload data you want to send to Android device(s)
// (it will be accessible via intent extras)
$data = array('message' => 'Hello World!');
// The recipient registration tokens for this notification
// https://developer.android.com/google/gcm/
$i...
Does Android keep the .apk files? if so where?
After android installs an application from the Marketplace, does it keep the .apk file?
19 Answers
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How to prevent IFRAME from redirecting top-level window
...ozilla.org/en-US/docs/Web/API/Window.onbeforeunload
In HTML5 you can use sandbox property. Please see Pankrat's answer below.
http://www.html5rocks.com/en/tutorials/security/sandboxed-iframes/
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