大约有 20,000 项符合查询结果（耗时：0.0363秒） [XML]
MySQL: @variable vs. variable. What's the difference?
...meters and declare the local variables:
DELIMITER //
CREATE PROCEDURE prc_test (var INT)
BEGIN
DECLARE var2 INT;
SET var2 = 1;
SELECT var2;
END;
//
DELIMITER ;
These variables are not prepended with any prefixes.
The difference between a procedure variable and a session-specific use...
How can I match a string with a regex in Bash?
...ed
If portability is not a concern, I recommend using [[ instead of [ or test as it is safer and more powerful. See What is the difference between test, [ and [[ ? for details.
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How many system resources will be held for keeping 1,000,000 websocket open? [closed]
...rrent TCP connections is not an issue.
I can affirm that based on our own tests (full disclosure: I am the CTO at Lightstreamer).
We had to demonstrate several times, to some of our customers, that 1 million connections can be reached on a single box (and not necessarily a super-monster machine). ...
MongoDB/NoSQL: Keeping Document Change History
...value: "This is the new body" }
],
tags: [
{ version: 1, value: [ "test", "trivial" ] },
{ version: 6, value: [ "foo", "test" ] }
],
comments: [
{
author: "joe", // Unversioned field
body: [
{ version: 3, value: "Something cool" }
]
},
{
au...
Difference between == and ===
...Swift also provides two identity operators (=== and !==), which you use to test whether two object references both refer to the same object instance.
Excerpt From: Apple Inc. “The Swift Programming Language.” iBooks. https://itun.es/us/jEUH0.l
...
How to convert from System.Enum to base integer?
...Enum enumValue)
{
return Convert.ToInt32(enumValue);
}
}
Test:
int x = DayOfWeek.Friday.ToInt();
Console.WriteLine(x); // results in 5 which is int value of Friday
EDIT 2: In the comments, someone said that this only works in C# 3.0. I just tested this in VS2005 like this and ...
Reading CSV files using C#
...ample code:
using (TextFieldParser parser = new TextFieldParser(@"c:\temp\test.csv"))
{
parser.TextFieldType = FieldType.Delimited;
parser.SetDelimiters(",");
while (!parser.EndOfData)
{
//Processing row
string[] fields = parser.ReadFields();
foreach (string...
How to use Elasticsearch with MongoDB?
...ttachments/1.6.0
These two plugins aren't necessary but they're good for testing queries and visualizing changes to your indexes.
bin/plugin --install mobz/elasticsearch-head
bin/plugin --install lukas-vlcek/bigdesk
Restart Elasticsearch.
sudo service elasticsearch restart
Finally index a co...
simple HTTP server in Java using only Java SE API
...erver.HttpHandler;
import com.sun.net.httpserver.HttpServer;
public class Test {
public static void main(String[] args) throws Exception {
HttpServer server = HttpServer.create(new InetSocketAddress(8000), 0);
server.createContext("/test", new MyHandler());
server.setEx...
Check whether HTML element has scrollbars
What's the fastest way of checking whether an element has scroll bars?
11 Answers
11
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