php關於mysql長串連問題

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1、當 函數 mysql_connect 的前三個參數（server username password）相同，並且第四個參數（new_link）不傳遞時候，重複調用 mysql_connect 是會返回相同的串連。

php代碼

<?php$db = mysql_connect(‘localhost‘,‘root‘,‘root‘);var_dump($db);$db2 = mysql_connect(‘localhost‘,‘root‘,‘root‘);var_dump($db2);sleep(10);

頁面列印資訊

resource(3) of type (mysql link) resource(3) of type (mysql link) 

mysql串連數

mysql> show full processlist;+----+------+-----------------+------+---------+------+-------+-----------------------+| Id | User | Host            | db   | Command | Time | State | Info                  |+----+------+-----------------+------+---------+------+-------+-----------------------+| 32 | root | localhost:54408 | NULL | Query   |    0 | NULL  | show full processlist || 44 | root | localhost:55278 | NULL | Sleep   |    3 |       | NULL                  |+----+------+-----------------+------+---------+------+-------+-----------------------+2 rows in set

2、當函數 mysql_connect 傳遞了第四個參數（new_link）後，再重複調用它。

php代碼

<?php$db = mysql_connect(‘localhost‘,‘root‘,‘root‘,1);var_dump($db);$db2 = mysql_connect(‘localhost‘,‘root‘,‘root‘,1);var_dump($db2);sleep(10);

頁面列印資訊

resource(3) of type (mysql link) resource(5) of type (mysql link) 

 

mysql串連數

mysql> show full processlist;+----+------+-----------------+------+---------+------+-------+-----------------------+| Id | User | Host            | db   | Command | Time | State | Info                  |+----+------+-----------------+------+---------+------+-------+-----------------------+| 32 | root | localhost:54408 | NULL | Query   |    0 | NULL  | show full processlist || 45 | root | localhost:55320 | NULL | Sleep   |    4 |       | NULL                  || 46 | root | localhost:55321 | NULL | Sleep   |    4 |       | NULL                  |+----+------+-----------------+------+---------+------+-------+-----------------------+

 

3、mysql_pconnect 持久串連

php代碼

<?php$db = mysql_pconnect(‘localhost‘,‘root‘,‘root‘);var_dump($db);$db2 = mysql_pconnect(‘localhost‘,‘root‘,‘root‘);var_dump($db2);

 

頁面列印資訊

resource(3) of type (mysql link persistent) resource(4) of type (mysql link persistent) 

 

mysql串連數

mysql> show full processlist;+----+------+-----------------+------+---------+------+-------+-----------------------+| Id | User | Host            | db   | Command | Time | State | Info                  |+----+------+-----------------+------+---------+------+-------+-----------------------+|  1 | root | localhost:55391 | NULL | Query   |    0 | NULL  | show full processlist ||  2 | root | localhost:55393 | NULL | Sleep   |    5 |       | NULL                  |+----+------+-----------------+------+---------+------+-------+-----------------------+

 

4、mysql_pconnect 加上第四個參數（new_link）即可 建立多個 持久串連

php代碼

<?php$db = mysql_pconnect(‘localhost‘,‘root‘,‘root‘,1);var_dump($db);$db2 = mysql_pconnect(‘localhost‘,‘root‘,‘root‘,1);var_dump($db2);

 

頁面列印資訊

resource(3) of type (mysql link persistent) resource(4) of type (mysql link persistent) 

 

mysql串連數

mysql> show full processlist;+----+------+-----------------+------+---------+------+-------+-----------------------+| Id | User | Host            | db   | Command | Time | State | Info                  |+----+------+-----------------+------+---------+------+-------+-----------------------+|  1 | root | localhost:55391 | NULL | Query   |    0 | NULL  | show full processlist ||  2 | root | localhost:55393 | NULL | Sleep   |  316 |       | NULL                  ||  3 | root | localhost:55418 | NULL | Sleep   |    4 |       | NULL                  |+----+------+-----------------+------+---------+------+-------+-----------------------+3 rows in set

 

5、總結：

函數 mysql_pconnetc 建立的 持久化串連 在php指令碼結束後，mysql的串連並不會立即結束。什麼時候結束，是由mysql自己管理。函數 mysql_colse 不能關閉 mysql_pconnetc 的串連。

函數 mysql_connetc 建立的 串連 在php指令碼結束後，mysql的串連也會相應結束。

 

php關於mysql長串連問題