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

mysqldump½øÐÐMysql ±¸·Ý


mysqlÊý¾Ý¿âµ¼³öÒªÓõ½MySQLµÄmysqldump¹¤¾ß£¬»ù±¾Ó÷¨ÊÇ£º 
 
shell> mysqldump [OPTIONS] database [tables]
 
Èç¹ûÄã²»¸ø¶¨ÈÎºÎ±í£¬Õû¸öÊý¾Ý¿â½«±»µ¼³ö¡£
ͨ¹ýÖ´ÐÐmysqldump --help£¬ÄãÄܵõ½ÄãmysqldumpµÄ°æ±¾Ö§³ÖµÄÑ¡Ïî±í¡£ 
×¢Ò⣬Èç¹ûÄãÔËÐÐmysqldumpûÓÐ--quick»ò--optÑ¡Ïmysq ......

[×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 ......

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( ......
© 2009 ej38.com All Rights Reserved. ¹ØÓÚE½¡ÍøÁªÏµÎÒÃÇ | Õ¾µãµØÍ¼ | ¸ÓICP±¸09004571ºÅ