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Rank function in MySQL
...ption is to use a ranking variable, such as the following:
SELECT first_name,
age,
gender,
@curRank := @curRank + 1 AS rank
FROM person p, (SELECT @curRank := 0) r
ORDER BY age;
The (SELECT @curRank := 0) part allows the variable initialization without requi...
How to access session variables from any class in ASP.NET?
I have created a class file in the App_Code folder in my application. I have a session variable
7 Answers
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MySQL Removing Some Foreign keys
...You can use this to find foreign key constraints: SELECT * FROM information_schema.table_constraints WHERE constraint_schema = '<your db name>' AND constraint_type = 'FOREIGN KEY'
– Gayan Dasanayake
Aug 26 '17 at 2:48
...
PDO closing connection
...>connection = new PDO();
$this->connection->query('KILL CONNECTION_ID()');
$this->connection = null;
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When is assembly faster than C?
...igh part of 64 bit integer multiplication: A portable version using uint64_t for 32x32 => 64-bit multiplies fails to optimize on a 64-bit CPU, so you need intrinsics or __int128 for efficient code on 64-bit systems.
_umul128 on Windows 32 bits: MSVC doesn't always do a good job when multiplying ...
Simplest way to detect a mobile device in PHP
...
Detect Mobile Browser
Download PHP script
Code:
<?php
$useragent=$_SERVER['HTTP_USER_AGENT'];
if(preg_match('/(android|bb\d+|meego).+mobile|avantgo|bada\/|blackberry|blazer|compal|elaine|fennec|hiptop|iemobile|ip(hone|od)|iris|kindle|lge |maemo|midp|mmp|netfront|opera m(ob|in)i|palm( os)?|...
Basic http file downloading and saving to disk in python?
...URLopener is deprecated.
And when used you will get error as below:
url_opener = urllib.URLopener() AttributeError: module 'urllib' has no
attribute 'URLopener'
So, try:
import urllib.request
urllib.request.urlretrieve(url, filename)
...
使用std::string作为std::map的key出错解决 - C/C++ - 清泛网 - 专注C/C++及内核技术
...0\vc\include\xstddef(180): error C2784: “bool std::operator <(const std::_Tree<_Traits> &,const std::_Tree<_Traits> &)”: 未能从“const std::string”为“const std::_Tree<_Traits> &”推导 模板 参数
1> c:\program files (x86)\microsoft visual studio 11.0\vc\include\xtree(2245...
Best algorithm for detecting cycles in a directed graph [closed]
...e following Wikipedia article:
http://en.wikipedia.org/wiki/Topological_sorting
has the pseudo-code for one algorithm, and a brief description of another from Tarjan. Both have O(|V| + |E|) time complexity.
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Extracting bits with a single multiplication
...and, namely SMT-LIB 2 input:
(set-logic BV)
(declare-const mask (_ BitVec 64))
(declare-const multiplicand (_ BitVec 64))
(assert
(forall ((x (_ BitVec 64)))
(let ((y (bvmul (bvand mask x) multiplicand)))
(and
(= ((_ extract 63 63) x) ((_ extract 63 63) y))
(= ...