[Dovecot] Updating Database records from a Plugin

Guys,

In the file /etc/dovecot-pgsql.conf I have driver = pgsql connect = host=localhost dbname=ivr.db user=ivr password=passwd default_pass_scheme = PLAIN password_query = SELECT password FROM embedded_device WHERE username='%u' user_query = SELECT home, uid, gid FROM embedded_device WHERE username='%u'

In the table embedded_device there is a field called PIN.

My plugin has the "user" and the "pin_value". What I want to do from the plugin is the following:

UPDATE embedded_device SET PIN=pin_value WHERE username=user;

Questions: Is there a way to locate the exiting database open connection? Is there a way to use the dovecot sql API to set the value of field?

I have been looking for examples and have not been very successful.

Regards,

John