PHP Usage Collation

PHP Common Collation

1, through the domain name to obtain the website IP address gethostbyname (' domain name ');?? such as gethostbyname (' www.baidu.com '); return IP address

Ip2long (' IP address ')? Convert IP address to Long data type
Long2ip (' long type ')?? Convert a long type to an IP address

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2. Copy the data from one table to another (two tables must be in the same structure)

INSERT into User_new (t_name,sex) SELECT t_name,sex from User_old

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3. How to establish MySQL sub-table

mysql> CREATE TABLE IF not EXISTS ' user1 ' (with ' id ' int (one) ' Not NULL auto_increment, ' name ' varchar) defaul T null, ' sex ' int (1) Not NULL default ' 0 ', PRIMARY KEY (' id '), engine=myisam default Charset=utf8 auto_ Increment=1; Query OK, 0 rows affected (0.05 sec) mysql> CREATE TABLE IF not EXISTS ' User2 ' (-id ' int ') not NULL Auto_incre ment, ' name ' varchar (+) default NULL, ' Sex ' int (1) NOT null default ' 0 ', PRIMARY KEY (' id ') ENG Ine=myisam DEFAULT Charset=utf8 auto_increment=1; Query OK, 0 rows affected (0.01 sec) mysql> INSERT into ' user1 ' (' name ', ' Sex ') VALUES (' Zhang Ying ', 0); Query OK, 1 row Affected (0.00 sec) mysql> INSERT into ' user2 ' (' name ', ' Sex ') VALUES (' Tank ', 1); Query OK, 1 row Affected (0.00 sec) mysql> CREATE TABLE IF not EXISTS ' AllUser ' (-id ' int ') not NULL AUTO_INCR Ement, ' name ' varchar (+) default NULL, ' Sex ' int (1) NOT null default ' 0 ', INDEX (ID)) type=mrg_my IsAM union= (user1,user2) insert_method=last auto_increment=1; Query OK, 0 rows affected, 1 Warning (0.00 sec) mysql> Select Id,name,sex from AllUser; +----+--------+-----+ | ID | name | sex | +----+--------+-----+ | 1 | Zhang Ying | 0 | | 1 | Tank | 1 | +----+--------+-----+ 2 rows in Set (0.00 sec) mysql> INSERT into ' alluser ' (' name ', ' Sex ') VALUES (' Tank2 ', 0); Query OK, 1 row Affected (0.00 sec) mysql> Select Id,name,sex from User2; +----+-------+-----+ | ID | name | sex | +----+-------+-----+ | 1 | Tank | 1 | | 2 | Tank2 | 0 | +----+-------+-----+ 2 rows in Set (0.00 sec)

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4. optimize limit and offset
MySQL limit works is to read N records first, and then discard the first n, read M want, so the greater the N, the worse the performance.
Optimized before Sql:select * from member ORDER by Last_active LIMIT 50,5
Optimized Sql:select * from Zb_sms_sendsmslog INNER JOIN (SELECT ID from Zb_sms_sendsmslog ORDER by ID limit 100000,100) as TMP using (ID)

The difference is that the SQL before optimization requires more I/O waste, because the index is read first, then the data is read, and then the unnecessary rows are discarded. The optimized SQL (sub-query) read-only index (Cover index) is available, and the required columns are read through member_id.

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5. The double quotation marks in the content after the Post submission Form are automatically preceded by a backslash

$b _str = $_post[$b _controlname]; if (GET_MAGIC_QUOTES_GPC ()) {$b _str = stripslashes ($b _str);}

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6, PHP use GBK encoding, the parameters with special Chinese characters such as (slightly

Execute before executing SQL

SET CHARACTER_SET_CONNECTION=GBK, CHARACTER_SET_RESULTS=GBK, character_set_client=binary

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? 7. Define variables in Smarty template

<{assign var= "i" value=0}> <{section name=book loop= $books}>

<{$i = $i +1}><{$i}>. title:<{$books [book].title}>
author:<{$books [book].author}>
isbn:<{$books [book].isbn}>
price:<{$books [book].price}>
<{/section}>

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8. Use similar for loop in Smarty

Use a section to simulate
{section Name=loop loop= $count}
ID: {$smarty. Section.loop.index}
{/section}


Assigning a value to count
$smarty->assign (' Count ', 5);

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