I've setup postfix to delivered my mail to a maildir located at

/var/spool/virtual_mailboxes/mydomain.com/myuser

My postgresql database called 'mails' has a user table setup as follows:

CREATE TABLE users (
  userid VARCHAR(128) NOT NULL,
  password VARCHAR(128),
  realname VARCHAR(128),
  uid INTEGER NOT NULL,
  gid INTEGER NOT NULL,
  home VARCHAR(128),
  mail VARCHAR(255),

  PRIMARY KEY (userid)
);

What would the query look like in my dovecot-pgsql.conf file to retrieve the appropriate INBOX information?

mine currently looks like this.
user_query = SELECT '/var/spool/virtual_mailboxes/'||home AS home, uid, gid FROM users WHERE userid = '%u'

The user authenticates fine via pop, yet I keeping getting the following error.
-ERR No INBOX for user