Kjell Rilbe wrote:

> Alexandre Benson Smith wrote:
>
>
>> Kjell Rilbe wrote:
>> > Now, as far as I know FB doesn't support this update ... from syntax,
>> > but is there any other way that FB could end up mixing data from
>> > multiple records in this subtle way instead of throwing an exception?
>> >
>> > Kjell
>> >
>>
>> Since you will need a sub-query like
>>
>> update
>> M
>> set
>> M.FieldA = (select FieldA from D where ...),
>> M.FieldB = (select FieldB from D where ...)
>>
>> you would get "multiple records" error, this kind of update requires a
>> single row returned
>>
>> So I don't think you could get such mixing with FB.
>>
>
> Thank you - I knew about that syntax for FB.

Yes, I am sure you know about it... I just put it to explain the only
way I know to acomplish the task you talked about...

> Just wondered if there are
> other ways to do it or if FB has other constructs that could suffer
> similar mixing as SQL Server.
>

AFAIK no.

> Somehow it seems typical of a Microsoft product to do strange unexpected
> things without telling anyone... And I though other FB enthusiasts like
> me might find this example amusing. :-)
>

So much time I stopped using MSSQL, I used version 6.5 around 1998.

But I remember something strange regarding null's become magically 0's

How bad a query could be executed if you have more than 5 relations joinned

Just you charset/collation (dictionary) for the whole database (or would
be for the whole server ?)

Row locking promoted to page locking promoted to table locking, terrible
if put together with bad clustered indices, well, is so easy to make the
"end" of a table a real bottleneck, every insert blocks the other
operations...

So long ago... perhaps MSSQL is a bit better now... :)

The only thing I missed when I switched from MSSQL to Firebird was an
application/service called SQL Trace, where you can monitor in real time
the queries and it's states, very good for debugging proposes. Our
monitoring tables and tools like Sinatica Monitor, filled that gap...

> Kjell
>

--
Alexandre Benson Smith
Development
THOR Software e Comercial Ltda
Santo Andre - Sao Paulo - Brazil
www.thorsoftware.com.br