[Zope] ZSQL subselect P

[Lee Marzke]

On 13-Mar-01 Jim Penny wrote:
> On Tue, Mar 13, 2001 at 03:14:00PM -0700, Casey Duncan wrote:
>> Lee Marzke wrote:
>> > 
>> > Hi,
>> > 
>> > I'm trying to use a subquery with the following SQL syntax and get an
>> > error.
>> > 
>> > SELECT * from return WHERE requestid = ( SELECT requestid from return
>> > ORDER BY
>> > requestid LIMIT 1 )
>> > 
>> > Each part of the queary works seperatly but not together.  Are their
>> > limitation
>> > on SQL statements that are allowed ?
>> > 
>> > Using Zope 2.3.0 and
>> > PostgresSQL 7.0.3
>> > ZPoPyDA-1.2.tar.gz
>> > PoPy-2.0.2.tar.gz
>> > 
> 
> I guarantee that (some) subselects can be done with this combo of software,
> use them all the time.  I am a bit concerned about the LIMIT clause in
> a subselect.
> 
> Would it not be far easier to say
> 
> SELECT * FROM return WHERE requestid = ( SELECT min(requestid) FROM return)
> ?

That works !

>>I'm no MySQL expert, but generally you would use the IN operator when
>>doing subselects. Can MySQL even do subselects??

Yes, I just switched ( rather painlessly ) from MySQL to PostgreSQL
because of random flackness with Solaris-7, Zope-2.3.0, and the MysqlDB
products.  The new PostgreSQL book by Momjian, ( Addison Wessley  )
is great.

Lee Marzke <lmarzke@kns.com>             13-Mar-01, 19:10:36
Kulicke & Soffa Industries
2101 Blair Mill Rd                       +1 215 784-6217
Willow Grove, PA 19090                   +1 215 784-6014 fax