大约有 46,000 项符合查询结果（耗时：0.0663秒） [XML]
Can I query MongoDB ObjectId by date?
...ObjectId embedded with a given datetime */
/* Accepts both Date object and string input */
function objectIdWithTimestamp(timestamp) {
/* Convert string date to Date object (otherwise assume timestamp is a date) */
if (typeof(timestamp) == 'string') {
timestamp = new Date(timestamp)...
What are copy elision and return value optimization?
....
Copy elision is an optimization implemented by most compilers to prevent extra (potentially expensive) copies in certain situations. It makes returning by value or pass-by-value feasible in practice (restrictions apply).
It's the only form of optimization that elides (ha!) the as-if rule - copy el...
Define variable to use with IN operator (T-SQL)
...@c_pos);
while @n_pos > 0
begin
insert into @tab (item) values (SUBSTRING(@list,@c_pos+1,@n_pos - @c_pos-1));
set @c_pos = @n_pos;
set @l_pos = @n_pos;
set @n_pos = CHARINDEX(',',@list,@c_pos+1);
end;
insert into @tab (item) values (SUBSTRING(@list,@l_pos+1,4000));
return;
end;...
Performance optimization strategies of last resort [closed]
...x4 matrices and 4-vectors of floats. Changing the code to carry around the extra empty slot and converting the calculation to floating point from fixed point allowed for a slightly less-accurate but much faster result.
– RBerteig
May 30 '09 at 2:19
...
Why isn't `int pow(int base, int exponent)` in the standard C++ libraries?
...ay to do an operation" as a constraint. Rightly so, because for example to_string and lambdas are both conveniences for things you could do already. I suppose one could interpret "only one way to do an operation" very loosely to allow both of those, and at the same time to allow almost any duplicati...
FragmentPagerAdapter Exists Only In Android.Support.V4.App (and not Android.App)
...ent = Android.App.Fragment;
namespace Support4
{
[Activity (Label = "@string/fragment_pager_support")]
[IntentFilter (new[]{Intent.ActionMain}, Categories = new[]{ "mono.support4demo.sample" })]
public class FragmentPagerSupport : Activity
//public class FragmentPagerSupport : Fragm...
How to ssh to vagrant without actually running “vagrant ssh”?
...s the simplified way which also works for automated solutions where adding extra ssh parameter -F is not straightforward
– laimison
Feb 2 '19 at 16:33
3
...
Postgresql SELECT if string contains
...
A proper way to search for a substring is to use position function instead of like expression, which requires escaping %, _ and an escape character (\ by default):
SELECT id FROM TAG_TABLE WHERE position(tag_name in 'aaaaaaaaaaa')>0;
...
Difference between @OneToMany and @ElementCollection?
...lection is not a collection of entities, but a collection of simple types (Strings, etc.) or a collection of embeddable elements (class annotated with @Embeddable).
It also means that the elements are completely owned by the containing entities: they're modified when the entity is modified, deleted...
C# 5 async CTP: why is internal “state” set to 0 in generated code before EndAwait call?
...rrect, as -1 normally means "finished". I could argue that we're giving an extra meaning to state 0 at the moment, but ultimately it doesn't really matter. The point of this question was finding out why the state is being set at all.
The value is relevant if the await ends in an exception which is ...