大约有 46,000 项符合查询结果（耗时：0.0640秒） [XML]
How to change the foreign key referential action? (behavior)
... means that if you delete a row from the parent table (Users in this case) all referencing rows from the child table (UserDetails) are also deleted.
– edruid
Jan 11 '18 at 14:20
1
...
how to return index of a sorted list? [duplicate]
...ray([2,3,1,4,5])
>>> vals
array([2, 3, 1, 4, 5])
>>> sort_index = numpy.argsort(vals)
>>> sort_index
array([2, 0, 1, 3, 4])
If not available, taken from this question, this is the fastest method:
>>> vals = [2,3,1,4,5]
>>> sorted(range(len(vals)), key=...
Default template arguments for function templates
Why are default template arguments only allowed on class templates? Why can't we define a default type in a member function template? For example:
...
How to hide first section header in UITableView (grouped style)
...
Actually, a better implementation (less likely to break in the future) is to use CGFLOAT_MIN instead of a hard-coded value. In other words, don't return 1.0f or 0.1f instead, return CGFLOAT_MIN If Apple ever changes the minimum a...
machine learning libraries in C# [closed]
...asses:
public class TrainingSet
{
private readonly List<string> _attributes = new List<string>();
private readonly List<List<object>> _examples = new List<List<object>>();
public TrainingSet(params string[] attributes)
{
_attributes.AddRang...
Where do I find the current C or C++ standard documents?
...9:1990 Hardcopy available from SAI Global ($88 + shipping)
You cannot usually get old revisions of a standard (any standard) directly from the standards bodies shortly after a new edition of the standard is released. Thus, standards for C89, C90, C99, C++98, C++03 will be hard to find for purchas...
How to print an exception in Python?
...rint the exception, it is better to use print(repr(e)); the base Exception.__str__ implementation only returns the exception message, not the type. Or, use the traceback module, which has methods for printing the current exception, formatted, or the full traceback.
– Martijn Pi...
getting exception “IllegalStateException: Can not perform this action after onSaveInstanceState”
... working perfectly for API < 11, and Force Closing on API > 11.
I really couldn't figure out what they changed inside the Activity lifecycle in the call to saveInstance, but I here is how I solved this :
@Override
protected void onSaveInstanceState(Bundle outState) {
//No call for super(...
How do I test for an empty JavaScript object?
...do you post answer including jQuery if the question is not about jQuery at all?
– Eru
Oct 1 '12 at 14:10
48
...
What does static_assert do, and what would you use it for?
...fined (as one would expect in a C++ library).
Contrast with having to actually compile SomeLibrary and your code, link everything, and run the executable only then to find out that you spent 30 minutes compiling an incompatible version of SomeLibrary.
@Arak, in response to your comment: yes, you ...