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Re: Try-except for flow control in reading Sqlite

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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

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Try-except for flow control in reading Sqlite Victor Hooi <victorhooi@gmail.com> - 2013-10-27 20:43 -0700
  Re: Try-except for flow control in reading Sqlite Steven D'Aprano <steve@pearwood.info> - 2013-10-28 06:18 +0000
    Re: Try-except for flow control in reading Sqlite Antoon Pardon <antoon.pardon@rece.vub.ac.be> - 2013-10-28 10:48 +0100
  Re: Try-except for flow control in reading Sqlite Chris Angelico <rosuav@gmail.com> - 2013-10-28 17:36 +1100
    Re: Try-except for flow control in reading Sqlite Victor Hooi <victorhooi@gmail.com> - 2013-10-27 23:57 -0700
      Re: Try-except for flow control in reading Sqlite Chris Angelico <rosuav@gmail.com> - 2013-10-28 18:01 +1100
        Re: Try-except for flow control in reading Sqlite Steven D'Aprano <steve@pearwood.info> - 2013-10-28 07:19 +0000
      Re: Try-except for flow control in reading Sqlite Chris Angelico <rosuav@gmail.com> - 2013-10-28 18:02 +1100
  Re: Try-except for flow control in reading Sqlite Burak Arslan <burak.arslan@arskom.com.tr> - 2013-10-28 10:17 +0200
  Re: Try-except for flow control in reading Sqlite Dennis Lee Bieber <wlfraed@ix.netcom.com> - 2013-10-28 19:43 -0400
    Re: Try-except for flow control in reading Sqlite Victor Hooi <victorhooi@gmail.com> - 2013-10-31 16:08 -0700
      Re: Try-except for flow control in reading Sqlite Dennis Lee Bieber <wlfraed@ix.netcom.com> - 2013-10-31 22:45 -0400

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