12/26/2012

PHP swap two variables

Some ways for swapping two variables

1. temporary variable
$a = 100;
$b=200;
$tmp = $a;
$a = $b;
$b = $tmp;

2. list
  $a = 100;
$b=200;
list($b,$a) = array($a,$b);

3. XOR
  $a = 100;
$b=200;

$a = $a ^ $b;
$b = $a ^ $b;
$a = $a ^ $b;

or
   $a = $b ^= $a ^= $b;

Note
1. The ways 1 and 2 can be used for any variable, including array, object, etc.
2. The way 3 can not be used on array, object.

PHP ternary operator

There are some ternary operators in PHP language.

1. if ... else
if($a==1){
echo 'good';
}
else{
echo 'error';
}

==>
echo ($a==1)? 'good': 'bad';

2. AND

if($a==1) echo 'good';

==>
($a==1) AND print( 'good';)

12/25/2012

Difference for Delete Table and Trncate Table - MySQL

Difference for Delete TABLE and Truncate TABLE

Delete TABLE VS Truncate TABLE

In order to remove all data from one table, you may use delete or truncate command. Just like

Syntax
Truncate [TABLE] table_name;

Delete [LOW_PRIORITY] [QUICK] [IGNORE] FROM table_name
[ WHERE where_condition]
[ORDER By .....]
[LIMIT row_count]

e.g.
Delete FROM table_name;

Truncate FROM table_name;

But there are some difference for them.

1. Speed

Truncate is faster than Delete.

Truncate will drop table and create a new table for you. Delete will just remove all data, but not table.

2. Return Value

Truncate will return 0 because it remove the table

Delete will return the number of removed rows.

3. Increment primary key (MyISAM Table)

Truncate will clear the increment key to 1.

Delete will not influence the increment key.

E.g. If the last increment key was 1000, the next inserted record key after Delete will be set to 10001, on the contrary, the new key after Truncate will be set to 1.

4. Remove parts of records or Where Clause

Truncate will all data

Delete can remove parts of records based on Where clause.

E.g. Delete FROM table_name WHERE id BETWEEN 100 AND 1000;

5. Language
Truncate is DDL (Data Definition Language).
Delete is DML (Data Manipulation Language).

6. Restore data
you nay use rollback to restore data after you execute Delete command
You can not restore the data after you execute Truncate command

All data will be lost permanently after you execute truncate or delete clause. So, please remember to check all data before you remove all data.

11/12/2012

two levels for CSS TAB MENU

CSS Tabs | unraveled

Home

About

Vision

Team

Culture

Careers

History

Sponsorship

News

Proof

Process

Expertise

Help

11/06/2012

__PHP_Incomplete_Class Object vs __PHP_Incomplete_Class_Name

When you meet '__PHP_Incomplete_Class_Name' by using unserialize , please confirm whether you have included the class file in serialized contents before you use unserialize function.

For example:

Include class

/*SimpleClass.php*/
class SimpleClass{
var $key;
function SimpleClass(){

}
function __set($name,$value){
$this->key[$name] = $value;
}
function __get($name){
return $this->key[$key];
}
}
?>

Write file

/*Store.php
*/
require_once './SimpleClass.php';
$SimpleClass = new SimpleClass;
$SimpleClass->keywords = 'Google';
@file_put_contents('./aaa.txt', serialize($SimpleClass));
?>

Wrong Read file

/*Read.php
*/
$SimpleClass = unserialize(file_get_contents('./aaa.txt'));
print_r($SimpleClass);
?>

Wrong Output

__PHP_Incomplete_Class Object
(
[__PHP_Incomplete_Class_Name] => SimpleClass
[key] => Array
(
[keywords] => Google
)
)

In order to resolve this problem, you have to include the class file in serialized contents before you use unserialize function.

Correct Read File

/*Read.php
*/
require_once './SimpleClass.php';
$SimpleClass = unserialize(file_get_contents('./aaa.txt'));
print_r($SimpleClass);
?>

Correct Output

SimpleClass Object
(
[key] => Array
(
[keywords] => Google
)
)

11/01/2012

resolutions for java version different from javac on centos 6.3

sudo java --verison

java version "1.6.0_24"

sudo javac --version //javac 1.7
javac 1.7.0_07

To install/ register a JVM use the following

1 /usr/sbin/alternatives --install "/usr/bin/java" "java" "/usr/java/default/bin/java" 2
2 /usr/sbin/alternatives --install "/usr/bin/javac" "javac" "/usr/java/default/bin/javac" 2

And to configure systemwide changes use
3 /usr/sbin/alternatives --configure java
or
/usr/sbin/alternatives --config java
4 /usr/sbin/alternatives --configure javac
or
/usr/sbin/alternatives --config javac

sudo java --verison

java version "1.7.0_07"

sudo javac --version //javac 1.7
javac 1.7.0_07

SQL_CALC_FOUND_ROWS + FOUND_ROWS()

When we want to list contents based on different pages, we have to do: one get a result set , another count the total number of rows. In general, we will use two query sql to complete this process.

1. SELECT id, title FROM articles WHERE TRUE LIMIT $limit, $start
2 SELECT count(id) as total FROM articles WHERE TRUE

From the above query, we may know the MySQL server will execute twice to scan all articles (query 1 will calculate result set size even when this is not needed). If the articles have more 1 million, the two queries need more times.

Fortunately, the MySQL server provide one methods to remember total records at executing the first query. So after executing the first, we just get the total records based on the first query, not executing the second query. Then we will save more half time. Now I give one example to complete this process.

3. SELECT SQL_CALC_FOUND_ROWS id, title FROM articles WHERE TRUE LIMIT $limit, $start
4. SELECT FOUND_ROWS() as total

The query 3 will scan all records, but the query 4 will not scan all records of the table. The executing efficiency will improve most.

For details about this method, please refer MySQL reference manual from http://dev.mysql.com/doc/refman/5.1/en/information-functions.html

Good luck.

10/23/2012

Import csv file from Select of MySQL

When you want to export csv file from MySQL, you may use phpMyAdmin as first choice. But you may use select clause to export csv file as another choice. The following is one example.

Table

name
Sam
Bush
....
Jone

mysql > select * from test_table where name LIKE "good" INTO OUTFILE "/tmp/export.csv" fields terminated by ',';

After you execute the above code, you mat get export.csv at your tmp directory. On the contrary, you may import from csv file.

mysql > load DATA LOCAL INFILE "/tmp/export.csv" INTO TABLE test_table fields terminated by "," LINES TERMINATED BY "\r\n";

connect mysql based on PHP

Before we use MySQL, we should create instance for MySQL. Now I give one example based on PHP source code.

Based on classic ways
1. connect MySQL

$link = mysql_connect("localhost", "root", "abc123456");
if (!$link) {
die('Could not connect: ' . mysql_error());
}

2. Select database
mysql_select_db("test_db", $link);

3. Execute select, update, insert .....

$result = mysql_query('SELECT email, name, pass FROM users ');
while ($row = mysql_fetch_assoc($result)) {
var_export($row);
}

4. Close MySQL
mysql_close($link);

Based on Security ways

1. connect MySQL
$link = new PDO('mysql:host=localhost;dbname=test_db', 'root', 'abc123456');

2. Execute select, update, insert .....
$sth = $pdo->query('SELECT email, name, pass FROM users');
foreach($sth as $row) {
var_export($row);
}

10/16/2012

Install Centos 6 and httpd+php5.3 +mysql5.5 on Windows Home 7

In order to install centos 6 with your windows, please prepare the following software

1. Download VM VirtualBox
http://www.oracle.com/technetwork/server-storage/virtualbox/downloads/index.html

2. Download Centos 6
http://ftp.jaist.ac.jp/pub/Linux/CentOS/6/isos/x86_64/

3. Download VirtualBox 4.2 for Linux
http://download.virtualbox.org/virtualbox/4.2.0_RC4/

Install Process
1. Install VM VirtualBox

2. Install centos

3. update yum
yum update
yum install gcc kernel-devel kernel-headers

4. install virtualLinuxAddtions

If you meet error with[Building the OpenGL support module [FAILED]] , please use the following command

export MAKE='/usr/bin/gmake -i'

./VBoxLinuxAdditions.run

if you still have errors, please try

/etc/init.d/vboxadd setup

5. install httpd
yum install httpd
#auto start
chkconfig httpd on

6. install php
yum install php

7. install mysql
## Remi Dependency on CentOS 6 and Red Hat (RHEL) 6 ##
## http://mirrors.ustc.edu.cn/fedora/epel/6/
rpm -Uvh http://download.fedoraproject.org/pub/epel/6/i386/epel-release-6-XXX.noarch.rpm

## CentOS 6 and Red Hat (RHEL) 6 ##
rpm -Uvh http://rpms.famillecollet.com/enterprise/remi-release-6.rpm

yum --enablerepo=remi,remi-test install mysql mysql-server
#auto start when PC start
chkconfig mysqld on

10/13/2012

install PHP5.3 on centos 5 or centos 6

Before you install PHP.3, you should update extra reposi. Please use the following url

$ wget http://dl.fedoraproject.org/pub/epel/5/x86_64/epel-release-5-4.noarch.rpm
$ wget http://rpms.famillecollet.com/enterprise/remi-release-5.rpm

$ sudo yum install php php-cli php-gd php-mysql php-mbstring

10/12/2012

get the value of more one PHP constants dynamically

using php's constant function

When you define many constants, it is difficult to call them when you use foreach or for clause. Now we may use constant function to realize them.

For example, we define

define('A_1','A');
define('A_2','B');
........
define('A_1000','KKKKKK');

when we use

$a = 88;

echo constant('A_'.$a );

or

for($i=50;$i<70 i="i" p="p"> echo constant('A_'.$i);
}

array_diff not support ojbect

array_diff for parameters does not support objects

e.g.
$a = array(
   'a',
   'b',
);
$b = array(
   'b',
   'c'
);

$c = array_diff($a, $b);

$c = array(1=>'b');

------------------------------

for object,

$a = array(
   new stdClass(),
   'b',
);
$b = array(
   'b',
   'c'
);

$c = array_diff($a, $b);

you will get error message
Catchable fatal error: Object of class stdClass could not be converted to string in...............

multi-language setting gettext for php

The following code creates multiple language site based on gettext from PHP.

Language:
English and Japanese
English: Hello
Japanese: こんにちは

Step 1: Get supported language from client

Method 1, auto-detect
<?php
$language = substr($_SERVER['HTTP_ACCEPT_LANGUAGE'], 0, 2);
if ($language == 'ja') {
$language = 'ja_JP';
}else{
$language = 'en_US';
}
?>

Method 2, $_GET-detect

<?php
$language = $_REQUEST ['lan'];
if ($language == 'ja') {
$language = 'ja_JP';
}else{
$language = 'en_US';
}
?>

Step 2: Set locale and default domain
<?php
putenv("LANG=$language");
setlocale(LC_ALL, $language);
$domain = 'domain_file_name';
bindtextdomain($domain, "/var/www/html/locale");
textdomain($domain);
?>

Step 3: Output
Method 1,
<?php
echo _('Hello');
?>
Method 1,
<?php
echo gettext('Hello');
?>

Now you may save all codes above with one php file with any name, here I use index.php, which looks like
------------------index.php--------------------------------

<?php

$language = $_REQUEST ['lan'];
if ($language == 'ja') {
$language = 'ja_JP';
}else{
$language = 'en_US';
}

putenv("LANG=$language");
setlocale(LC_ALL, $language);
$domain = 'domain_file_name';
bindtextdomain($domain, "/var/www/html/locale");
textdomain($domain);

echo _('Hello');
?>

-------------------------------------------

Step 4: Create po file based on $domain setting, the command looks like

xgettext -d domain_file_name index.php --from-code=utf-8

After executing the command, you may get one new file, whose name is 'domain_file_name.po'. Open it
-------------------------domain_file_name.po------------------------------
# SOME DESCRIPTIVE TITLE.
# Copyright (C) YEAR THE PACKAGE'S COPYRIGHT HOLDER
# This file is distributed under the same license as the PACKAGE package.
# FIRST AUTHOR , YEAR.
#
#, fuzzy
msgid ""
msgstr ""
"Project-Id-Version: PACKAGE VERSION\n"
"Report-Msgid-Bugs-To: \n"
"POT-Creation-Date: 2012-10-12 14:41+0900\n"
"PO-Revision-Date: YEAR-MO-DA HO:MI+ZONE\n"
"Last-Translator: FULL NAME \n"
"Language-Team: LANGUAGE \n"
"MIME-Version: 1.0\n"
"Content-Type: text/plain; charset=CHARSET\n"
"Content-Transfer-Encoding: 8bit\n"

#: index.php:16
msgid "Hello"
msgstr ""

---------------------------------------------------------

Then you may change

1. charset=CHARSET -> charset=utf-8

2. msgstr "" -> msgstr="こんにちは"

------------------------------------------------------------

Step 5: Create mo file based on domain_file_name.po, the command looks like
msgfmt domain_file_name.po

Now you have created one file, whose name is domain_file_name.mo

Step 6: Move domain_file_name.mo to special directory like

locale

/en_US

/LC_MESSAGES

/ domain_file_name.mo

/ja_JP