Path: csiph.com!v102.xanadu-bbs.net!xanadu-bbs.net!feeder.erje.net!eu.feeder.erje.net!feeds.phibee-telecom.net!newsfeed.xs4all.nl!newsfeed2.news.xs4all.nl!xs4all!newsgate.cistron.nl!newsgate.news.xs4all.nl!post.news.xs4all.nl!not-for-mail
Return-Path: <burak.arslan@arskom.com.tr>
X-Original-To: python-list@python.org
Delivered-To: python-list@mail.python.org
X-Spam-Status: OK 0.004
X-Spam-Evidence: '*H*': 0.99; '*S*': 0.00; 'schema': 0.05; 'exist,': 0.09; 'lookup': 0.09; 'try:': 0.09; 'burak': 0.16; 'flow.': 0.16; 'from:addr:arskom.com.tr': 0.16; 'from:addr:burak.arslan': 0.16; 'from:name:burak arslan': 0.16; 'message-id:@arskom.com.tr': 0.16; 'received:arskomhosting.com': 0.16; 'sqlite': 0.16; 'subject:flow': 0.16; 'wrote:': 0.18; 'file,': 0.19; 'select': 0.22; 'this?': 0.23; 'header:User-Agent:1': 0.23; 'controlling': 0.24; 'entries': 0.24; 'script': 0.25; 'header:In-Reply-To:1': 0.27; "doesn't": 0.30; 'database,': 0.30; 'existence': 0.31; 'file': 0.32; 'open': 0.33; 'table': 0.34; 'there,': 0.34; "i'd": 0.34; 'created': 0.35; 'except': 0.35; 'something': 0.35; 'acceptable': 0.36; 'hi,': 0.36; 'should': 0.36; 'list': 0.37; 'to:addr:python-list': 0.38; 'to:addr:python.org': 0.39; 'remove': 0.60; 'protect': 0.79; 'victor': 0.84
Date: Mon, 28 Oct 2013 10:17:26 +0200
From: Burak Arslan <burak.arslan@arskom.com.tr>
User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:24.0) Gecko/20100101 Thunderbird/24.0
MIME-Version: 1.0
To: python-list@python.org
Subject: Re: Try-except for flow control in reading Sqlite
References: <ac7cf18f-d4f4-41ef-966d-a35d2d0e39a8@googlegroups.com>
In-Reply-To: <ac7cf18f-d4f4-41ef-966d-a35d2d0e39a8@googlegroups.com>
X-Enigmail-Version: 1.5.2
Content-Type: text/plain; charset=ISO-8859-1
Content-Transfer-Encoding: 7bit
X-BeenThere: python-list@python.org
X-Mailman-Version: 2.1.15
Precedence: list
List-Id: General discussion list for the Python programming language <python-list.python.org>
List-Unsubscribe: <https://mail.python.org/mailman/options/python-list>, <mailto:python-list-request@python.org?subject=unsubscribe>
List-Archive: <http://mail.python.org/pipermail/python-list/>
List-Post: <mailto:python-list@python.org>
List-Help: <mailto:python-list-request@python.org?subject=help>
List-Subscribe: <https://mail.python.org/mailman/listinfo/python-list>, <mailto:python-list-request@python.org?subject=subscribe>
Newsgroups: comp.lang.python
Message-ID: <mailman.1686.1382948833.18130.python-list@python.org>
Lines: 29
NNTP-Posting-Host: 2001:888:2000:d::a6
X-Trace: 1382948833 news.xs4all.nl 15878 [2001:888:2000:d::a6]:42920
X-Complaints-To: abuse@xs4all.nl
Xref: csiph.com comp.lang.python:57798

On 10/28/13 05:43, Victor Hooi wrote:
> Hi,
>
> I'd like to double-check something regarding using try-except for controlling flow.
>
> I have a script that needs to lookup things in a SQLite database.
>
> If the SQLite database file doesn't exist, I'd like to create an empty database, and then setup the schema.
>
> Is it acceptable to use try-except in order to achieve this? E.g.:
>
>     try:
>         # Try to open up the SQLite file, and lookup the required entries
>     except OSError:
>         # Open an empty SQLite file, and create the schema
>

this doesn't protect against a partially-created schema. do you have
something like a "version" table in your database as the last created
table? you can check for its existence in the except block and if it's
not there, you should remove the file and re-create it.

to get a list of tables:

    select * from sqlite_master where type='table';

best,
burak