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Is there a MySQL option/feature to track history of changes to records?
...
For example, if you have a table like this:
CUSTOMER
---------
CUSTOMER_ID PK
CUSTOMER_NAME
CUSTOMER_ADDRESS
and you wanted to keep track over time, you would amend it as follows:
CUSTOMER
------------
CUSTOMER_ID PK
CUSTOMER_VALID_FROM PK
CUSTOMER_VALID_UNTIL PK
CUSTOMER_STAT...
Regular Expression for alphanumeric and underscores
...that contains only those characters (or an empty string), try
"^[a-zA-Z0-9_]*$"
This works for .NET regular expressions, and probably a lot of other languages as well.
Breaking it down:
^ : start of string
[ : beginning of character group
a-z : any lowercase letter
A-Z : any uppercase letter
0-...
Is there a way to specify an “empty” C# lambda expression?
...000/svg\"\u003e\u003cpath d=\"M46.1709 9.17788C46.1709 8.26454 46.2665 7.94324 47.1084 7.58816C47.4091 7.46349 47.7169 7.36433 48.0099 7.26993C48.9099 6.97997 49.672 6.73443 49.672 5.93063C49.672 5.22043 48.9832 4.61182 48.1414 4.61182C47.4335 4.61182 46.7256 4.91628 46.0943 5.50789C45.7307 4.9328 4...
Get time difference between two dates in seconds
...ly be closed as a duplicate, take a look here stackoverflow.com/questions/1322732/…
– Juan Cortés
Mar 15 '17 at 11:16
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What exactly does += do in python?
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In Python, += is sugar coating for the __iadd__ special method, or __add__ or __radd__ if __iadd__ isn't present. The __iadd__ method of a class can do anything it wants. The list object implements it and uses it to iterate over an iterable object appending each...
What is a message pump?
...essage(&msg);
DispatchMessage(&msg);
}
The GetMessage() Win32 API retrieves a message from Windows. Your program typically spends 99.9% of its time there, waiting for Windows to tell it something interesting happened. TranslateMessage() is a helper function that translates keyboard...
What is the logic behind the “using” keyword in C++?
...000/svg\"\u003e\u003cpath d=\"M46.1709 9.17788C46.1709 8.26454 46.2665 7.94324 47.1084 7.58816C47.4091 7.46349 47.7169 7.36433 48.0099 7.26993C48.9099 6.97997 49.672 6.73443 49.672 5.93063C49.672 5.22043 48.9832 4.61182 48.1414 4.61182C47.4335 4.61182 46.7256 4.91628 46.0943 5.50789C45.7307 4.9328 4...
rails 3.1.0 ActionView::Template::Error (application.css isn't precompiled)
...ris Muench
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How to search for a part of a word with ElasticSearch
... nGram just as a filter. Here is my setup:
{
"index": {
"index": "my_idx",
"type": "my_type",
"analysis": {
"index_analyzer": {
"my_index_analyzer": {
"type": "custom",
"tokenizer": "standard",
"filter": [
"lowercase",
...
关于php的socket初探 - 更多技术 - 清泛网 - 专注C/C++及内核技术
...塞的古老模型：属于同步阻塞 IO 模型，代码如下：
socket_server.php
<?php
/**
* SocketServer Class
* By James.Huang <shagoo#gmail.com>
**/
set_time_limit(0);
class SocketServer
{
private static $socket;
function SocketServer($port)
{ ...