[Dovecot] Complex MySQL query in dovecot-sql.conf

[Timo Neuvonen]

Is there some limit for the maximum length of the line in dovecot-sql.conf?
In particular, I would be writing a long MySQL password query.

And further, can a long line be somehow split to several pieces? I tried the
common unix-style way of putting backslash as the last character of the
first line, but it results in an error immediatedly while restarting
Dovecot (while parsing the conf, ie. not a MySQL error):

(in conf:)
password_query = SELECT user, password FROM users\
 WHERE user='%u' AND active='Y'

(results in log, line 88 refers to line starting with 'WHERE':)
auth(default): Error in configuration file /etc/dovecot-mysql.conf line 88:
Expecting '='


The example above is just the beginning, what comes to my question about a
long line. I would be checking %r (remote ip) against user-specific allowed
ip-address ranges given in the database.
Actually, I'd like to use some MySQL user-defined variables within my query,
for example to keep only the 3 highest octets of the IPv4 representation of
%r (eg. '192.168.0') so I could easily check against allowed /24 networks
stored in the database. That seems to run into another problem.
A very simplified example what happens when I try to define a variable
within the query:

(in conf, split to two lines for news only:)
password_query = SET @yes='Y'; SELECT user, password FROM users
WHERE user='%u' AND active=@yes

(results in log:)
Password query failed: You have an error in your SQL syntax; check the
manual that corresponds to your MySQL server version for the right syntax to
use near '; SELECT user, password FROM users WHERE user='testi'
AND active=@yes' at line 1

Anyway, a similar one-line construct works from the MySQL command line:
SET @yes='Y'; SELECT user, password FROM users WHERE user='testi'
AND active=@yes;
(reults the following:)
+-------+----------+
| user  | password |
+-------+----------+
| testi | 123      |
+-------+----------+


Any ideas? Am I doing something in a completely wrong way?
Of course, split lines & variables are not absolutely necessary, they just
would improve readability & shorten the query. But if there is no limit on
the length of the query, I propably can write everything as a one long
SELECT command...

I'm trying all this on Fedora Core 5, having
- dovecot-1.0-0.beta8.2.fc5
- mysql-5.0.22-1.FC5.1


Regards,
Timo Neuvonen