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Rake just one migration
...n a single migration that changed and needed to be re-run independently of all other migrations. Fire up the console and do this:
>> require 'db/migrate/your_migrations.rb'
=> ["YourMigrations"]
>> YourMigrations.up
=> etc... as the migration runs
>> YourMigration.down
Mor...
Programmatically saving image to Django ImageField
...import File # you need this somewhere
import urllib
# The following actually resides in a method of my model
result = urllib.urlretrieve(image_url) # image_url is a URL to an image
# self.photo is the ImageField
self.photo.save(
os.path.basename(self.url),
File(open(result[0], 'rb'))
...
SQL - using alias in Group By
...ceptions though: MySQL and Postgres seem to have additional smartness that allows it.
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Is it safe to resolve a promise multiple times?
... rejected), that is it for a defered object - it is done.
If you should call then(...) on it's promise again, you should immediately get the (first) resolved/rejected result.
Additional calls to resolve() will not (should not?) have any effect. Not sure what happens if you attempt to reject a de...
How to determine if a list of polygon points are in clockwise order?
... Jan 4 '16 at 18:32
Roberto Bonvallet
25.9k55 gold badges3737 silver badges5555 bronze badges
answered Jul 22 '09 at 15:02
...
Retargeting solution from .Net 4.0 to 4.5 - how to retarget the NuGet packages?
...ers a feature that makes this a lot simpler: just do update-package -reinstall -ignoreDependencies from the Package Manager Console.
NuGet 2.0 doesn't handle re-targeting your applications very well. In order to change your packages' target frameworks, you must uninstall and reinstall the packages...
What does Connect.js methodOverride do?
...en you can use app.delete and app.put in Express instead of using app.post all the time (thus more descriptive, verbose):
Backend:
// the app
app.put('/users/:id', function (req, res, next) {
// edit your user here
});
Client logic:
// client side must be..
<form> ...
<input type=...
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.
...
What is the difference between SessionState and ViewState?
... saved on the server, ViewState is saved in the page.
Session state is usually cleared after a period of inactivity from the user (no request happened containing the session id in the request cookies).
The view state is posted on subsequent post back in a hidden field.
...
When to use inline function and when not to use it?
...at inline is a hint or request to compiler and its used to avoid function call overheads.
14 Answers
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