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Django self-referential foreign key
I'm kind of new to webapps and database stuff in general so this might be a dumb question. I want to make a model ("CategoryModel") with a field that points to the primary id of another instance of the model (its parent).
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How do I get the information from a meta tag with JavaScript?
... edited Oct 20 '18 at 0:55
neiker
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answered Sep 23 '11 at 5:25
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Delete a key from a MongoDB document using Mongoose
....0 you can do:
User.update({_id: user._id}, {$unset: {field: 1 }}, callback);
And since version 2.4, if you have an instance of a model already you can do:
doc.field = undefined;
doc.save(callback);
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Android 'Unable to add window — token null is not for an application' exception
...- are you trying to create Dialog with an application context? Something like this:
new Dialog(getApplicationContext());
This is wrong. You need to use an Activity context.
You have to try like:
new Dialog(YourActivity.this);
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Synchronization vs Lock
java.util.concurrent API provides a class called as Lock , which would basically serialize the control in order to access the critical resource. It gives method such as park() and unpark() .
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Why does 'continue' behave like 'break' in a Foreach-Object?
...he return instead of the continue. This return returns from the script block which is invoked by ForEach-Object on a particular iteration, thus, it simulates the continue in a loop.
1..100 | ForEach-Object {
if ($_ % 7 -ne 0 ) { return }
Write-Host "$($_) is a multiple of 7"
}
There is a ...
Date vs DateTime
I am working on a program that requires the date of an event to get returned.
12 Answers
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What is the difference between Debug and Release in Visual Studio?
...important because the compiler is very advanced and can do some pretty tricky low-level improving of your code. As a result some lines of your code might get left without any instructions at all, or some might get all mixed up. Step-by-step debugging would be impossible. Also, local variables are of...
Default constructor with empty brackets
Is there any good reason that an empty set of round brackets (parentheses) isn't valid for calling the default constructor in C++?
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Provisioning Profiles menu item missing from Xcode 5
... I don't have a menu item for Library - Provisioning Profiles, and I don't know what could have happened. I restarted the computer, tried some things, but I really have no idea what I could do. How can I fix this problem?
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