PHP commonly used sorting 1. get the website IP address gethostbyname ('domain name') through the domain name ');?? For example, gethostbyname ('www .baidu.com '); returns the IP address ip2long ('IP address ')? Convert an IP address to a long data type long2ip ('long type ')?? Sort out lo PHP frequently used
1. get the website IP address gethostbyname ('domain name') through the domain name ');?? For example, gethostbyname ('www .baidu.com '); IP address returned
Ip2long ('IP address ')? Convert an IP address to a long data type
Long2ip ('long type ')?? Convert long type to IP address
?
2. copy data from one table to another (the two tables must have the same structure)
Insert into user_new (t_name, sex) SELECT t_name, sex FROM user_Old
?
3. create a table in mysql
Mysql> create table if not exists 'user1' (-> 'id' int (11) not null AUTO_INCREMENT,-> 'name' varchar (50) default 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 (11) NOT NULL AUTO_INCREMENT, -> 'name' varchar (50) default null,-> 'sex' int (1) not null default '0',-> primary key ('id')->) ENGINE = MyISAM default charset = utf8 AUTO_INCREMENT = 1; Query OK, 0 rows affected (0.01 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 (11) not null AUTO_INCREMENT,-> 'name' varchar (50) default null,-> 'sex' int (1) not null default '0',-> INDEX (id) ->) TYPE = MRG_MyISAM 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 | | 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)
?
?
4,Optimize limit and offset
MySQL's limit mechanism is to read n records first, then discard the first n records and read m records. Therefore, the larger n records, the worse the performance.
SQL before optimization: SELECT * FROM member ORDER BY last_active LIMIT 50, 5
After optimization, 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 statement before optimization requires more I/O waste, because the index is read first, data is read again, and unnecessary rows are discarded. After optimization, the read-only index (Cover index) of the SQL statement (subquery) can be used to read the required columns through member_id.
?
5. POSTSubmit formInDouble quotation marksAllAutomaticIn frontA backslash is added.
$ B _Str = $ _ POST [$ B _ControlName]; if (get_magic_quotes_gpc () {$ B _Str = stripslashes ($ B _Str );}
?
6. When Php uses GBK encoding, the parameter contains special Chinese characters, such)
Run the SQL statement first.
SET character_set_connection = GBK, character_set_results = GBK, character_set_client = binary
?
?
? 7. variables defined in the 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}>
?
8. Use a for loop similar
Simulate using a section
{Section name = loop = $ count}
Id: {$ smarty. section. loop. index}
{/Section}
Assign count values
$ Smarty-> assign ('count', 5 );