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How to 'bulk update' with Django?
...ings like incrementing rows:
from django.db.models import F
Entry.objects.all().update(n_pingbacks=F('n_pingbacks') + 1)
See the documentation.
However, note that:
This won't use ModelClass.save method (so if you have some logic inside it won't be triggered).
No django signals will be emitte...
Android: failed to convert @drawable/picture into a drawable
In my drawable folder I have a few images and they all reference perfect, but when I try and add any more images with the exact same size in the same folder, and try to reference it, is flags up an error "Failed to convert @drawable/picture into a drawable" . I have tried the same image with a diff...
Why would I use Scala/Lift over Java/Spring? [closed]
...over it. From my perspective and experience, Java Annotations and Spring really minimizes the amount of coding that you have to do for an application. Does Scala/Lift improve upon that?
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What is the closest thing Windows has to fork()?
I guess the question says it all.
13 Answers
13
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Real world use cases of bitwise operators [closed]
...checksums, parity, stop bits, flow control algorithms, and so on, which usually depend on the logic values of individual bytes as opposed to numeric values, since the medium may only be capable of transmitting one bit at a time.
Compression, Encryption
Both of these are heavily dependent on bitwise ...
Why are #ifndef and #define used in C++ header files?
...his case HEADERFILE_H) is defined. Then if it's not defined, it defines it and continues to the rest of the page.
When the code is included again, the first ifndef fails, resulting in a blank file.
That prevents double declaration of any identifiers such as types, enums and static variables.
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Difference between std::result_of and decltype
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result_of was introduced in Boost, and then included in TR1, and finally in C++0x. Therefore result_of has an advantage that is backward-compatible (with a suitable library).
decltype is an entirely new thing in C++0x, does not restrict only to return type of a function, and is a language fe...
Cron job every three days
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The answer is not correct because neither suggestion actually runs the job every 3 days. 0 0 */3 * * means run on the 1st, 4th, 7th, etc. (*/3 means 1-31/3 means 1,4,7...31) so the gap will be smaller at the end of the month. (It'll run 2 days in a row if the previous month had 3...
ng-app vs. data-ng-app, what is the difference?
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It seems like such a waste of CPU cycles to manually strip off data- and x-. Why can't the HTML validation rules be changed to accept ng- stuff?
– DaveAlger
May 13 '15 at 14:43
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How do I delete an Azure storage account containing a leased blob?
...unt can be deleted.
Notes:
This applies even if you've already deleted all of your Virtual Machines and it shows 0; there still will be artifacts under the disks tab.
Disks are detached from a deleted VM asynchronously, it may take a few minutes after the VM is deleted for this field to clear up...