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Entity Framework - Code First - Can't Store List
... Great solution for EF Core. Although it seems to have an issue whit char to string conversion. I had to implement it like such: .HasConversion( v => string.Join(";", v), v => v.Split(new char[] { ';' }, StringSplitOptions.RemoveEmptyEntries));...
Dokan虚拟磁盘开发实战 - 操作系统(内核) - 清泛网 - 专注C/C++及内核技术
...Dokan.pas里的定义
_DOKAN_OPTIONS = packed record
DriveLetter: WCHAR; // Drive letter to be mounted
ThreadCount: Word; // Number of threads to be used
DebugMode: Boolean;
UseStdErr: Boolean;
UseAltStream: Boolean;
UseKeepAlive: Boolean;
GlobalContext: Int64; ...
Why do we need fibers
...> #<Enumerator: [1, 2, 3]:reverse_each>
irb(main):002:0> "abc".chars
=> #<Enumerator: "abc":chars>
irb(main):003:0> 1.upto(10)
=> #<Enumerator: 1:upto(10)>
These Enumerators are Enumerable objects, and their each methods yield the elements which would have been yie...
T-SQL CASE Clause: How to specify WHEN NULL
... firts+space+last name.
this will work as long as the default setting for concatenation with null strings is set:
SET CONCAT_NULL_YIELDS_NULL ON
this shouldn't be a concern since the OFF mode is going away in future versions of SQl Server
...
How to know the size of the string in bytes?
...
You can use encoding like ASCII to get a character per byte by using the System.Text.Encoding class.
or try this
System.Text.ASCIIEncoding.Unicode.GetByteCount(string);
System.Text.ASCIIEncoding.ASCII.GetByteCount(string);
...
How important is the order of columns in indexes?
...st selective and the other the reverse.
CREATE TABLE Table1(MostSelective char(800), SecondMost TINYINT, Least CHAR(1), Filler CHAR(4000) null);
CREATE TABLE Table2(MostSelective char(800), SecondMost TINYINT, Least CHAR(1), Filler CHAR(4000) null);
CREATE NONCLUSTERED INDEX MyINDX on Table1(Mos...
Inheriting from a template class in c++
... create objects from any other class). Another such class would be Area<char>. Note that those are completely different classes, which have nothing in common except for the fact that they were generated from the same class template.
Since Area is not a class, you cannot derive the class Recta...
How do I print to the debug output window in a Win32 app?
...cro that depending on your build options either maps to OutputDebugStringA(char const*) or OutputDebugStringW(wchar_t const*). In the later case you will have to supply a wide character string to the function. To create a wide character literal you can use the L prefix:
OutputDebugStringW(L"My outp...
SQL SELECT speed int vs varchar
...
Int comparisons are faster than varchar comparisons, for the simple fact that ints take up much less space than varchars.
This holds true both for unindexed and indexed access. The fastest way to go is an indexed int column.
As I see you've tagged the ques...
JavaScript style for optional callbacks
...tions
( rest
, combs =>
callback (combs .concat (combs .map (c => [ x, ...c ])))
)
console.log (combinations (['A', 'B', 'C']))
// [ []
// , [ 'C' ]
// , [ 'B' ]
// , [ 'B', 'C' ]
// , [ 'A' ]
// , [ 'A', 'C' ]
// , [ 'A', 'B' ]
// , [ 'A', 'B...