Path: csiph.com!news.redatomik.org!aioe.org!.POSTED!not-for-mail
From: =?UTF-8?Q?Arne_Vajh=c3=b8j?= <arne@vajhoej.dk>
Newsgroups: comp.lang.java.programmer
Subject: Re: Testing the functionality of sub classes
Date: Sun, 20 Aug 2017 11:14:26 -0400
Organization: Aioe.org NNTP Server
Lines: 40
Message-ID: <onc90h$1vgf$1@gioia.aioe.org>
References: <87fucnh2wu.fsf@munus.decebal.nl> <subclasses-20170819193036@ram.dialup.fu-berlin.de> <87y3qffim5.fsf@munus.decebal.nl> <ona7tq$igi$1@dont-email.me> <87pobrf855.fsf@munus.decebal.nl> <slrnopiu4a.o2q.avl@logic.at> <87ziaue74o.fsf@munus.decebal.nl> <87valie4xz.fsf@munus.decebal.nl> <onc3s5$1ns5$1@gioia.aioe.org> <slrnopj7la.o2q.avl@logic.at>
NNTP-Posting-Host: PBuS014lhzVyHjLbXmo/ZQ.user.gioia.aioe.org
Mime-Version: 1.0
Content-Type: text/plain; charset=utf-8; format=flowed
Content-Transfer-Encoding: 8bit
X-Complaints-To: abuse@aioe.org
User-Agent: Mozilla/5.0 (Windows NT 6.1; WOW64; rv:52.0) Gecko/20100101 Thunderbird/52.3.0
Content-Language: en-US
X-Notice: Filtered by postfilter v. 0.8.2
Xref: csiph.com comp.lang.java.programmer:37318

On 8/20/2017 10:33 AM, Andreas Leitgeb wrote:
> Arne Vajhøj <arne@vajhoej.dk> wrote:
>> On 8/20/2017 9:36 AM, Cecil Westerhof wrote:
>>> Cecil Westerhof <Cecil@decebal.nl> writes:
>>>> Just to satisfy my curiosity I executed (I do not like the formatting,
>>>> but that is what Eclipse does):
>>>>       try (
>>>>               Statement stmt = conn.createStatement();
>>>>               ResultSet rsOne = stmt.executeQuery("SELECT 12 AS twelve");
>>>>               ResultSet rsTwo = stmt.executeQuery("SELECT 'Hello World!' AS message")
>>>>               ) {
>>>>           System.out.println(stmt);
>>>>           System.out.println(rsOne);
>>>>           System.out.println(rsTwo);
>>>>       }
>>>>
>>>> And this gives:
>>>>       org.sqlite.jdbc4.JDBC4Statement@685f4c2e
>>>>       org.sqlite.jdbc4.JDBC4ResultSet@7daf6ecc
>>>>       org.sqlite.jdbc4.JDBC4ResultSet@7daf6ecc
>>>>
>>>> So yes, it is like you said: the ResultSet is reused. Is also more
>>>> logical. I jumped to a conclusion.
>>>
>>> With a H2 database I get:
>>>       stat0
>>>       rs0: null
>>>       rs1: org.h2.result.LocalResult@1bc6a36e columns: 1 rows: 1 pos: -1
>>
>> That is what happens when you try and do unsupported things: you get
>> undefined/implementation specific behavior. Bad!
> 
> In this particular case the "undefined/implementation specific behavior"
> is ResultSet-implementation's toString().  That's why I suggested to use
> System.identityHashCode().

It is more than that. SQLite reuse result set object - H2 does not.

Arne