大约有 4,700 项符合查询结果（耗时：0.0152秒） [XML]
What is non-blocking or asynchronous I/O in Node.js?
...chronous, blocking operations is how some web servers like ones in Java or PHP handle IO or network requests. If your code reads from a file or the database, your code "blocks" everything after it from executing. In that period, your machine is holding onto memory and processing time for a thread th...
Characters allowed in a URL
...789abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ.-_~
Note: Before PHP 5.3.0 rawurlencode() encoded ~ because of RFC 1738. But this was replaced by RFC 3986 so its safe to use, now. But I do not understand why for example {} are encoded through rawurlencode() because they are not mentioned i...
Alter MySQL table to add comments on columns
...re.net/2010/04/15/add-comments-to-column-mysql/
http://bugs.mysql.com/bug.php?id=64439
share
|
improve this answer
|
follow
|
...
What is the best way to convert seconds into (Hour:Minutes:Seconds:Milliseconds) time?
What is the best way to convert seconds into (Hour:Minutes:Seconds:Milliseconds) time?
13 Answers
...
How to set HTTP headers (for cache-control)?
...
You can set the headers in PHP by using:
<?php
//set headers to NOT cache a page
header("Cache-Control: no-cache, must-revalidate"); //HTTP 1.1
header("Pragma: no-cache"); //HTTP 1.0
header("Expires: Sat, 26 Jul 1997 05:00:00 GMT"); // Date...
LaTeX Optional Arguments
...1 and #2 in the {<definition>}--nothing new so far.
But by adding a second optional argument to this \newcommand
(the [YYY]) the first argument (#1) of the newly defined
command \example is made optional with its default value being YYY.
Thus the usage of \example is either:
\example{B...
SQL keys, MUL vs PRI vs UNI
...mysql> create table penguins (foo INT);
Query OK, 0 rows affected (0.01 sec)
mysql> desc penguins;
+-------+---------+------+-----+---------+-------+
| Field | Type | Null | Key | Default | Extra |
+-------+---------+------+-----+---------+-------+
| foo | int(11) | YES | | NULL ...
Swapping column values in MySQL
...d
mysql> drop table if exists swaptest;
Query OK, 0 rows affected (0.03 sec)
mysql> create table swaptest (X int,Y int);
Query OK, 0 rows affected (0.12 sec)
mysql> INSERT INTO swaptest VALUES (1,2),(3,4),(-5,-8),(-13,27);
Query OK, 4 rows affected (0.08 sec)
Records: 4 Duplicates: 0 Wa...
Resumable downloads when using PHP to send the file?
We are using a PHP scripting for tunnelling file downloads, since we don't want to expose the absolute path of downloadable file:
...
How to calculate time elapsed in bash script?
...
Bash has a handy SECONDS builtin variable that tracks the number of seconds that have passed since the shell was started. This variable retains its properties when assigned to, and the value returned after the assignment is the number of seco...