From: | Jon Barnett <jbarnett(at)pobox(dot)com> |
---|---|
To: | "'Peter Mount'" <petermount(at)it(dot)maidstone(dot)gov(dot)uk>, "'pgsql-interfaces(at)hub(dot)org'" <pgsql-interfaces(at)hub(dot)org> |
Subject: | RE: [INTERFACES] JDBC next() method |
Date: | 1999-04-14 14:37:03 |
Message-ID: | 01BE86D8.15D52260.jbarnett@pobox.com |
Views: | Raw Message | Whole Thread | Download mbox | Resend email |
Thread: | |
Lists: | pgsql-interfaces |
On Wednesday, 14 April 1999 23:18, Peter Mount
[SMTP:petermount(at)it(dot)maidstone(dot)gov(dot)uk] wrote:
> This looks ok.
>
> queryResult is null if there was an error in the query, so you should
> check for that.
>
> However, normal use would have the result parsed within a
> while(queryResult.next()) {} loop, so your interpretation is correct.
I don't think the query should give an error - as the query is at least
syntactically correct. Certainly, if I check for a queryResult == null, the
condition doesn't occur for an empty table.
I just had a quick browse on some old JDBC notes and it looks like the correct
solution is:
queryResult = dbStatement.executeQuery("select max(history_id) from history");
queryResult.next();
nextID = queryResult.getLong(1) + 1;
if (queryResult.wasNull())
nextID = 0;
Note: queryResult.wasNull() only works immediately after calling a getxxx
method.
Thanks.
JonB.
From | Date | Subject | |
---|---|---|---|
Next Message | Peter Mount | 1999-04-14 14:51:39 | RE: [INTERFACES] JDBC next() method |
Previous Message | Peter Mount | 1999-04-14 13:18:23 | RE: [INTERFACES] JDBC next() method |