大约有 48,000 项符合查询结果（耗时：0.0410秒） [XML]
SQL Server: SELECT only the rows with MAX(DATE)
... HAVING t1.DateEntered = MAX(t2.DateEntered))
This is the fastest of all the queries supplied above. The query cost came in at 0.0070668.
The preferred answer above, by Mikael Eriksson, has a query cost of 0.0146625
You may not care about the performance for such a small sample, but in large...
Length of a JavaScript object
...an break enumerations in various libraries. Adding methods to Object is usually safe, though.
Here's an update as of 2016 and widespread deployment of ES5 and beyond. For IE9+ and all other modern ES5+ capable browsers, you can use Object.keys() so the above code just becomes:
var size = Object...
Get all directories within directory nodejs
...
Here's a shorter, syncronous version of this answer that can list all directories (hidden or not) in the current directory:
const { lstatSync, readdirSync } = require('fs')
const { join } = require('path')
const isDirectory = source => lstatSync(source).isDirectory()
const getDirectori...
How to get RGB values from UIColor?
...rView.backgroundColor;//line 2
CGColorRef colorRef = [color CGColor];
int _countComponents = CGColorGetNumberOfComponents(colorRef);
if (_countComponents == 4) {
const CGFloat *_components = CGColorGetComponents(colorRef);
CGFloat red = _components[0];
CGFloat green = _components[1...
Difference between fprintf, printf and sprintf?
...on>
#include <stdarg.h>
#include <stdio.h>
struct exception_fmt : std::exception
{
exception_fmt(char const* fmt, ...) __attribute__ ((format(printf,2,3)));
char const* what() const throw() { return msg_; }
char msg_[0x800];
};
exception_fmt::exception_fmt(char const* fm...
How to declare a global variable in JavaScript?
...s available only in browsers. Could you edit you answer to make it work in all environments? See How to get the global object in JavaScript?
– Michał Perłakowski
Nov 30 '16 at 15:50
...
Why use Ruby's attr_accessor, attr_reader and attr_writer?
...write classes which will work correctly no matter how their public API is called.
class Person
attr_accessor :age
...
end
Here, I can see that I may both read and write the age.
class Person
attr_reader :age
...
end
Here, I can see that I may only read the age. Imagine that it is set ...
Using Git, how could I search for a string across all branches?
Using Git, how could I search within all files in all local branches for a given string?
5 Answers
...
Define variable to use with IN operator (T-SQL)
... myColumn in (SELECT id FROM myIdTable WHERE id > 10)
2) Using dynamically concatenated TSQL
DECLARE @sql varchar(max)
declare @list varchar(256)
select @list = '1,2,3'
SELECT @sql = 'SELECT * FROM myTable WHERE myColumn in (' + @list + ')'
exec sp_executeSQL @sql
3) A possible third ...
Setting default value for TypeScript object passed as argument
...
Actually, there appears to now be a simple way. The following code works in TypeScript 1.5:
function sayName({ first, last = 'Smith' }: {first: string; last?: string }): void {
const name = first + ' ' + last;
console.log(na...