大约有 16,000 项符合查询结果（耗时：0.0279秒） [XML]
In SQL, what's the difference between count(column) and count(*)?
...ot
[edit] added this code so that people can run it
create table #bla(id int,id2 int)
insert #bla values(null,null)
insert #bla values(1,null)
insert #bla values(null,1)
insert #bla values(1,null)
insert #bla values(null,1)
insert #bla values(1,null)
insert #bla values(null,null)
select count(*),...
Simple proof that GUID is not unique [closed]
...se the ram we allocated up front.
// Actually, these are pointless too.
//GC.KeepAlive(reserveSomeRam);
//GC.Collect();
}
Console.WriteLine("{0:u} - Built bigHeapOGuids, contains {1} of them.", DateTime.Now, bigHeapOGuids.LongCo...
Java Enum definition
...ss StatusCode extends Enum<StatusCode>
Now if you check the constraints, we've got Enum<StatusCode> - so E=StatusCode. Let's check: does E extend Enum<StatusCode>? Yes! We're okay.
You may well be asking yourself what the point of this is :) Well, it means that the API for Enum ...
Using member variable in lambda capture list inside a member function
...here your puzzle object might already be destroyed, you'll need to make an intermediate, local copy:
vector<vector<int> > tmp(grid);
auto lambda = [tmp](){}; // capture the local copy per copy
† I'm simplifying - Google for "reaching scope" or see §5.1.2 for all the gory details....
Difference between decimal, float and double in .NET?
...
float and double are floating binary point types. In other words, they represent a number like this:
10001.10010110011
The binary number and the location of the binary point are both encoded within the value.
decimal is a floating decimal point type. In other ...
Do I need quotes for strings in YAML?
...s values
I, however, use double-quotes for integer values that need to be converted to strings like:
docker-compose version like version: "3.8"
port numbers like "8080:8080"
However, for special cases like booleans, floats, integers, and other cases, where using double-quotes for the entry values...
Performance of Find() vs. FirstOrDefault() [duplicate]
Got an interesting outcome searching for Diana within a large sequence of a simple reference type having a single string property.
...
Core pool size vs maximum pool size in ThreadPoolExecutor
...
There is an interesting method allowCoreThreadTimeOut(boolean) which allows core threads to be killed after given idle time. Setting this to true and setting core threads = max threads allows the thread pool to scale between 0 and max th...
How to Set Opacity (Alpha) for View in Android
..., attrs);
}
public AlphaTextView(Context context, AttributeSet attrs, int defStyle) {
super(context, attrs, defStyle);
}
@Override
public boolean onSetAlpha(int alpha) {
setTextColor(getTextColors().withAlpha(alpha));
setHintTextColor(getHintTextColors().withAlpha(alpha));
...
How to get a list of column names on Sqlite3 database?
...mething like this... but it don't work create temporary table TmpCols (cid integer, name text, type text, nn bit, dflt_value, pk bit); .mode insert TmpCols .output cols PRAGMA TABLE_INFO('yourtable'); .read cols .mode csv .output stdout
– Jason
Jan 5 '12 a...