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Mysql error 1452 - Cannot add or update a child row: a foreign key constraint fails
...d FROM sourcecodes) should help to get rid of those IDs. Or if null is not allowed in sourcecode_id, then remove those rows or add those missing values to the sourcecodes table.
– naXa
Feb 23 '16 at 14:28
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Java: Detect duplicates in ArrayList?
...ole collection into a Set (using the Set(Collection) constructor or Set.addAll), then see if the Set has the same size as the ArrayList.
List<Integer> list = ...;
Set<Integer> set = new HashSet<Integer>(list);
if(set.size() < list.size()){
/* There are duplicates */
}
Up...
Why is debugging better in an IDE? [closed]
...hat an IDE debugger will give you over trace messages in code:
View the call stack at any point in time, giving you a context for your current stack frame.
Step into libraries that you are not able to re-compile for the purposes of adding traces (assuming you have access to the debug symbols)
Chan...
Check synchronously if file/directory exists in Node.js
... Note that fs.exists() is deprecated, but fs.existsSync() is not. (The
callback parameter to fs.exists() accepts parameters that are
inconsistent with other Node.js callbacks. fs.existsSync() does not
use a callback.)
You've specifically asked for a synchronous check, but if you can use an ...
In Windows Azure: What are web role, worker role and VM role?
... to host the application in Windows Azure, so I created a web role. I actually want to know what these roles are for. What is their significance coding wise or storage wise?
...
GitHub: How to make a fork of public repository private?
...plicate the repo as others said (details here):
Create a new repo (let's call it private-repo) via the Github UI. Then:
git clone --bare https://github.com/exampleuser/public-repo.git
cd public-repo.git
git push --mirror https://github.com/yourname/private-repo.git
cd ..
rm -rf public-repo.git
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How to determine the first and last iteration in a foreach loop?
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@Twan How is point #3 right? Or relevant at all to this question since it involves HTML? This is a PHP question, clearly... and when it comes to mark-up semantics, it's down to a much deeper facts than "a proper blahblah is always better than blahblah (this is not even...
What does “&” at the end of a linux command mean?
...s will not stay alive after the shell session is closed. SIGHUP terminates all running processes. By default anyway. If your command is long-running or runs indefinitely (ie: microservice) you need to pr-pend it with nohup so it remains running after you disconnect from the session:
nohup sh my_scr...
Difference between a Postback and a Callback
I keep on hearing this words ' callback ' and ' postback ' tossed around.
What is the difference between two ?
6 Answers...
Interface or an Abstract Class: which one to use?
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I was trying all day to understand the usages of abstract and interface classes, your post made it all clear. Thanks a lot Alan
– afarazit
May 21 '11 at 12:51
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