Path: csiph.com!aioe.org!.POSTED!not-for-mail
From: =?UTF-8?Q?Arne_Vajh=c3=b8j?= <arne@vajhoej.dk>
Newsgroups: comp.lang.java.programmer
Subject: Re: Which databases are the most used with Java
Date: Tue, 15 Aug 2017 11:51:23 -0400
Organization: Aioe.org NNTP Server
Lines: 39
Message-ID: <omv59o$j4v$1@gioia.aioe.org>
References: <87y3qovwjb.fsf@munus.decebal.nl> <omovh9$ad2$1@news.albasani.net> <87tw1bx2c9.fsf@munus.decebal.nl> <slrnop0881.o2q.avl@logic.at> <87a833wzcx.fsf@munus.decebal.nl> <evbal8Fs681U1@mid.individual.net> <87pobz9yv5.fsf@munus.decebal.nl> <afdc32bc-17ff-4ee9-ade0-c7345f805585@googlegroups.com> <87h8x9pfi8.fsf@munus.decebal.nl> <omukv5$m10$1@newsreader4.netcologne.de> <877ey5ngtu.fsf@munus.decebal.nl> <6b0c0b97-8517-4f08-b512-fc3f3054fbb6@googlegroups.com> <87378soq8a.fsf@munus.decebal.nl> <54246758-9876-4f41-a7ac-c2fff223a9e0@googlegroups.com>
NNTP-Posting-Host: LO3gx2vFpREKIznvPHDlcg.user.gioia.aioe.org
Mime-Version: 1.0
Content-Type: text/plain; charset=utf-8; format=flowed
Content-Transfer-Encoding: 7bit
X-Complaints-To: abuse@aioe.org
User-Agent: Mozilla/5.0 (Windows NT 6.1; WOW64; rv:45.0) Gecko/20100101 Thunderbird/45.8.0
X-Notice: Filtered by postfilter v. 0.8.2
Xref: csiph.com comp.lang.java.programmer:37248

On 8/15/2017 11:43 AM, Eric Douglas wrote:
> Here's another simple example, look one Statement instance, two ResultSet instance.
>
>      public static void main(final String[] args) {
>           try {
>                Connection conn = DriverManager.getConnection(db_connect_string, db_userid, db_password);
>                Statement stmt = conn.createStatement(ResultSet.TYPE_SCROLL_INSENSITIVE, ResultSet.CONCUR_READ_ONLY);
>                ResultSet rs = stmt.executeQuery("SELECT table_name FROM information_schema.tables");
>                System.out.println(stmt.getClass());
>                rs.last();
>                System.out.println(rs.getRow());
>                rs.close();
>                rs = stmt.executeQuery("SELECT name from sys.columns");

I don't think I would reuse the variable.

>                rs.last();
>                System.out.println(rs.getRow());
>                rs.close();
>                stmt.close();
>                conn.close();
>           } catch (SQLException e) {
>                e.printStackTrace();
>           }
>      }

> The close methods are optional.

Connection close is definitely not optional.

>                                 Anything you ultimately fail to close should
> close itself in a cleanup section.

Yes. Either catch or finally should close. Or the new try with resource
should be used instead.

Arne