Isconnected () returns true, although mysql server went to zend framework

Question

I am working on a zend framework application. I am running a single mailing script on the server. Somehow I get a response after 5 minutes from the SMTP server, while the mysql server left due to mysql timeout. Checked that the connection is active or not. I use

$db->isConnected();

but it always returns true, although the mysql server is gone. I can not understand the meaning of isConnected. Anyone explain me how db connection works?

Answer 1

From the manual (my emphasis):

1.7.2 , isConnected(). , . , , . , . .

http://framework.zend.com/manual/1.12/en/zend.db.adapter.html

, , - " ? ?", TCP.

( : , SQL-, , , (, $db->query('SELECT 1')) , .)