问题描述
我有一个旧版PHP/MySQL应用程序,该应用程序调用mysql_connect().现有的大量下游代码使用此连接直接或通过包装程序进行mysql_query()
调用.
I have a legacy PHP/MySQL app that calls mysql_connect(). Tons of existing downstream code makes mysql_query()
calls, either directly or through wrappers, using this connection.
对于我在应用程序上开发的新代码,我想开始使用PDO.
For new code that I develop on the app, I would like to start using PDO.
如果我使用相同的主机/用户/密码/dbname凭据建立PDO连接,那么我是否很幸运,在幕后,PHP将重新使用原始连接?还是PHP会创建到服务器的两个不同的连接(虽然完全可以理解,但这是不希望的)?
If I make a PDO connection using the same host/user/pass/dbname credentials, might I be so lucky that under the hood, PHP will re-use the original connection? Or will PHP create two distinct connections to the server (undesirable, albeit totally understandable)?
谢谢!
推荐答案
如果您使用两种不同的API(即mysql_*
和PDO),PHP将生成两个不同的连接.
If you are using two different APIs (i.e. mysql_*
and PDO), PHP will generate two different connections.
并且,作为证明",请考虑以下部分代码:
And, as a "proof", consider this portion of code :
$db = mysql_connect('localhost', 'USER', 'PASSWORD');
$pdo = new PDO('mysql://@localhost/astralblog', 'USER', 'PASSWORD');
sleep(5);
运行此命令将在MySQL服务器上导致两个截然不同的连接-它将休眠5秒钟:
Running this will cause two distinct connections, on the MySQL server -- which will sleep for 5 seconds :
mysql> show processlist;
+----+------------+-----------------+------------+---------+------+-------+------------------+
| Id | User | Host | db | Command | Time | State | Info |
+----+------------+-----------------+------------+---------+------+-------+------------------+
| 41 | astralblog | localhost:46551 | astralblog | Sleep | 188 | | NULL |
| 42 | astralblog | localhost:46552 | astralblog | Sleep | 188 | | NULL |
| 43 | astralblog | localhost | astralblog | Query | 0 | NULL | show processlist |
| 64 | astralblog | localhost | NULL | Sleep | 4 | | NULL |
| 65 | astralblog | localhost | NULL | Sleep | 4 | | NULL |
+----+------------+-----------------+------------+---------+------+-------+------------------+
5 rows in set (0,00 sec)
(所讨论的连接是最后两个,当我启动PHP脚本时出现,并在5秒钟后消失)
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