Re: MySql bug?

Hi,

> In MySql I create this table:
> 
> CREATE TABLE `prova` (
> `Gruppo` int(11) NOT NULL default '0',
> `Prog` int(11) NOT NULL default '0',
> `Descrizione` varchar(100) default '',
> PRIMARY KEY  (`Gruppo`, `Prog`)
> ) TYPE=MyISAM;
> 
> Running this:
> UPDATE Prog SET Prog=Prog+1 WHERE Gruppo=16 AND Prog>=1
> 
> I get "Duplicate entry".
> 
> Is this a MySql bug? How can I do this?

This is not a bug, but a shortcoming of MyISAM tables not being
transactional. But you can overcome this by using the following query:

  UPDATE Prog SET Prog=Prog+1 WHERE Gruppo=16 AND Prog>=1
  ORDER BY Prog DESC;


Rgds,
Indrek

-- 
|  Indrek Siitan, MySQL AB, Support Engineer & Bugmaster
|  Uuemõisa, Haapsalu, Estonia
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