[Dovecot] 1.0 RC1 status

[Andrey Panin]

On 175, 06 24, 2006 at 09:35:22 +0300, Timo Sirainen wrote:
> On Thu, 2006-06-22 at 16:01 +0400, Andrey Panin wrote:
> > On 169, 06 18, 2006 at 07:31:05PM +0300, Timo Sirainen wrote:
> > > On Sun, 2006-06-18 at 19:59 +0400, Andrey Panin wrote:
> > > > Here is a big problem with transaction support in MySQL driver: it simpy 
> > > > doesn't work :( sql_transaction_commit_s() function fails and MySQL reports
> > > > this error: 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 
> > > > ';UPDATE ...
> > > > 
> > > > Looks like mysql_query() chokes if query contains semicolon.
> > > 
> > > Did you really test with the few days old code? Because I added this
> > > which fixed it for me:
> > > 
> > > #ifdef CLIENT_MULTI_STATEMENTS
> > > 	/* Updates require this because everything is committed in one large
> > > 	   SQL statement. */
> > > 	db->client_flags |= CLIENT_MULTI_STATEMENTS;
> > > #endif
> > 
> > Yes, it works with MySQL >= 4.1. Seems like I need to upgrade MySQL on my home
> > computer. 
> 
> I thought earlier versions of MySQL allowed multi-statements by
> default.. Or is it maybe earlier versions of the server?

Earlier versions of the server do not work. Tested with MySQL client 5.0 and
MySQL server 4.0.

> > But sql_update() still fails, because mysql_store_result() returns 
> > NULL if the query didn't return data. Of course UPDATE queries do not return
> > data. Attached patch solved this problem for me, but I'm not sure how good it
> > is for common use. Please take a look.
> 
> Right. I fixed this a while ago also by checking mysql_errno() return
> values.

Unfortunately I don't think it's fixed :(

> > 
> > > > IMHO we must just use MySQL BEGIN/COMMIT/ROLLBACK and let users care
> > > > about transaction safety of their databases.
> > > 
> > > I don't think that's such a good idea, because if transactions aren't
> > > supported (and isn't that how MySQL is most commonly still used?) the
> > > rollback command does nothing and that can cause problems (like wrongly
> > > updating quota).
> > 
> > Currently users with MySQL < 4.1 will get obscure SQL syntax error message
> > and think "Where this fscking semicolon came from ?!". May be we should 
> > somehow notify user that update isn't actually supported...
> 
> The good thing is that currently the only place in Dovecot where SQL
> updates are done is the dict quota backend, which not many people are
> using. :)

I'm working on the second user :)

>  Would be nice to get proper error message about it, but I'm
> not really sure how to do it. Especially if the only broken combination
> is MySQL client < 4.1 + MySQL server > 4.1.


-- 
Andrey Panin		| Linux and UNIX system administrator
pazke at donpac.ru		| PGP key: wwwkeys.pgp.net
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