Ò׽ؽØÍ¼Èí¼þ¡¢µ¥Îļþ¡¢Ãâ°²×°¡¢´¿ÂÌÉ«¡¢½ö160KB

Mysql Explain Ïê½â[Ç¿ÁÒÍÆ¼ö]

Mysql Explain Ïê½â
Ò».Óï·¨
explain < table_name >
ÀýÈç: explain select * from t3 where id=3952602;
¶þ.explainÊä³ö½âÊÍ
+----+-------------+-------+-------+-------------------+---------+---------+-------+------+-------+
| id | select_type | table | type  | possible_keys     | key     | key_len | ref   | rows | Extra |
+----+-------------+-------+-------+-------------------+---------+---------+-------+------+-------+
1.id
  ÎÒµÄÀí½âÊÇSQLÖ´ÐеÄ˳ÀûµÄ±êʶ,SQL´Ó´óµ½Ð¡µÄÖ´ÐÐ.
ÀýÈç:
mysql> explain select * from (select * from ( select * from t3 where id=3952602) a) b;
+----+-------------+------------+--------+-------------------+---------+---------+------+------+-------+
| id | select_type | table      | type   | possible_keys     | key     | key_len | ref  | rows | Extra |
+----+-------------+------------+--------+-------------------+---------+---------+------+------+-------+
|  1 | PRIMARY     | <derived2> | system | NULL              | NULL    | NULL    | NULL |    1 |       |
|  2 | DERIVED     | <derived3> | system | NULL              | NULL    | NULL    | NULL |    1 |       |
|  3 | DERIVED     | t3         | const  | PRIMARY,idx_t3_id | PRIMARY | 4       |      |    1 |       |
+----+-------------+------------+--------+-------------------+---------+---------+------+------+-------+
ºÜÏÔÈ»ÕâÌõSQLÊÇ´ÓÀïÏòÍâµÄÖ´ÐÐ,¾ÍÊÇ´Óid=3 ÏòÉÏÖ´ÐÐ.
2. select_type
¾ÍÊÇselectÀàÐÍ,¿ÉÒÔÓÐÒÔϼ¸ÖÖ
(1) SIMPL


Ïà¹ØÎĵµ£º

[×ªÔØ]mysqlµÄСÎÊÌâ

mysql error number 2003   
Can't connect to MySQL server xxx.xxx.xxx.xxx (10061)
ÔÚubuntu 9.04ÖÐĬÈϰ²×°ÁËmysql£¬Ä¬ÈÏÖ»Äܱ¾µØ·ÃÎÊ£¬googleÁËһϣº
²ÉÓÃ
µÇ¼µ½MySQL·þÎñÆ÷¶Ë£¬ÔÚmysql¿âÏÂÖ´ÐÐ
grant all on *.* to 'remote'@'172.16.21.39' identified by 'password';
¼´¿É

Èç¹ûÒªÉèÖÃÎ ......

mysql´æ´¢ÒýÇæÖ® InnoDB

InnoDB¸ÅÊö
InnoDB¸øMySQLÌṩÁ˾ßÓÐÌá½»£¬»Ø¹öºÍ±ÀÀ£»Ö¸´ÄÜÁ¦µÄÊÂÎñ°²È«£¨ACID¼æÈÝ£©´æ´¢ÒýÇæ¡£InnoDBËø¶¨ÔÚÐм¶²¢ÇÒÒ²ÔÚSELECTÓï¾äÌṩһ¸öOracle·ç¸ñÒ»ÖµķÇËø¶¨¶Á¡£ÕâÐ©ÌØÉ«Ôö¼ÓÁ˶àÓû§²¿ÊðºÍÐÔÄÜ¡£Ã»ÓÐÔÚInnoDBÖÐÀ©´óËø¶¨µÄÐèÒª£¬ÒòΪÔÚInnoDBÖÐÐм¶Ëø¶¨ÊʺϷdz£Ð¡µÄ¿Õ¼ä¡£InnoDBÒ²Ö§³ÖFOREIGN KEYÇ¿ÖÆ¡£ÔÚSQL²éÑ¯Ö ......

MySQL´¥·¢Æ÷

MySQL´¥·¢Æ÷
Ò»¡¢ MySQL´¥·¢Æ÷¸ÅÄî
MySQL5.0ÒÔÉϰ汾֧³Ö´¥·¢Æ÷£¬´¥·¢Æ÷ÊÇÓë±íÓйصÄÃüÃûÊý¾Ý¿â¶ÔÏ󣬵±±í³öÏÖÌØ¶¨Ê¼þʱ£¬½«¼¤»î¸Ã¶ÔÏó¡£
¶þ¡¢ MySQL´¥·¢Æ÷Óï·¨
CREATE TRIGGER trigger_name trigger_time trigger_event
       ON tbl_name FOR EACH ROW trigger_stmt
trigger ......

PHPÖеÄMYSQL³£Óú¯Êý×ܽá

PHPÖеÄMYSQL³£Óú¯Êý×ܽá
1¡¢mysql_connect()-½¨Á¢Êý¾Ý¿âÁ¬½Ó
¸ñʽ£º
    resource mysql_connect([string hostname [:port] [:/path/to/socket] [, string username] [, string password]])
Àý£º
    $conn = @mysql_connect("localhost", "username", "password") or dir( ......

MySQLʵÏÖÊ÷µÄ±éÀú

¾­³£ÔÚÒ»¸ö±íÖÐÓи¸×Ó¹ØÏµµÄÁ½¸ö×ֶΣ¬±ÈÈçempnoÓëmanager£¬ÕâÖֽṹÖÐÐèÒªÓõ½Ê÷µÄ±éÀú¡£ÔÚOracle ÖпÉÒÔʹÓÃconnect by¼òµ¥½â¾öÎÊÌ⣬²Î¼ûhttp://blog.csdn.net/ylqmf/archive/2010/01/11/5172866.aspx£¬µ«MySQL 5.1Öл¹²»Ö§³Ö£¨¾Ý˵ÒÑÄÉÈëto doÖУ©£¬Òª×Ô¼ºÐ´¹ý³Ì»òº¯ÊýÀ´ÊµÏÖ¡£
Ò»¡¢½¨Á¢²âÊÔ±íºÍÊý¾Ý£º
view plaincop ......
© 2009 ej38.com All Rights Reserved. ¹ØÓÚE½¡ÍøÁªÏµÎÒÃÇ | Õ¾µãµØÍ¼ | ¸ÓICP±¸09004571ºÅ