大约有 44,868 项符合查询结果（耗时：0.0540秒） [XML]
Primary key or Unique index?
At work we have a big database with unique indexes instead of primary keys and all works fine.
15 Answers
...
Copy file or directories recursively in Python
...hutil.copytree ) but I haven't found any function that handles both. Sure, it's trivial to check whether you want to copy a file or a directory, but it seems like a strange omission.
...
Math functions in AngularJS bindings
...
You have to inject Math into your scope, if you need to use it as
$scope know nothing about Math.
Simplest way, you can do
$scope.Math = window.Math;
in your controller.
Angular way to do this correctly would be create a Math service, I guess.
...
Should import statements always be at the top of a module?
...
Module importing is quite fast, but not instant. This means that:
Putting the imports at the top of the module is fine, because it's a trivial cost that's only paid once.
Putting the imports within a function will cause calls to that function to...
How far can memory leaks go?
... memory is cleaned up at least when the program terminates. Are there any situations where leaked memory won't be collected when the program terminates, or crashes?
...
How to find serial number of Android device?
...
TelephonyManager tManager = (TelephonyManager)myActivity.getSystemService(Context.TELEPHONY_SERVICE);
String uid = tManager.getDeviceId();
getSystemService is a method from the Activity class. getDeviceID() will return the MDN or MEID of the device depending on which radio t...
Why can't an anonymous method be assigned to var?
...
Others have already pointed out that there are infinitely many possible delegate types that you could have meant; what is so special about Func that it deserves to be the default instead of Predicate or Action or any other possibility? And, for lambdas, why is it obvious that ...
How to use Namespaces in Swift?
The documentation only mentions nested types, but it's not clear if they can be used as namespaces. I haven't found any explicit mentioning of namespaces.
...
What does this Google Play APK publish error message mean?
...e. Clicking "Deactivate" on the dropdown next to version 3 appeared to fix it.
My guess is that this is a very-poorly-worded error message meaning something like "your original APK hasn't been published to all the update servers yet, so some of them may miss that version entirely". But it's a bit o...
Storing Images in DB - Yea or Nay?
...is? I'm more of a type to store the location in the filesystem, than store it directly in the DB.
56 Answers
...