[Interest] Best way to handle database migrations on QML

[Daniel França]

It's kind of similar to what Django ORM does, I would definitely consider
this approach for a next iteration :)
My problem is how to handle the version parameter to LocalStorage.

Em sex, 23 de out de 2015 às 13:28, Gian Maxera <gmaxera at gmail.com>
escreveu:

> Hello Daniel,
> I also develop website using Laravel (a PHP framework), and for migration
> they use a special table called “migration” with two column: “migration”
> and “batch”.
> The “migration” is a unique name identifying the migration.
> “batch” is a incremental number indicating where the migration has been
> done.
> Suppose in the table you see:
>
> “Migration 1”, 1
> “Migration 2”, 1
> “Migration 3”, 2
> “Migration 4”, 3
> “Migration 5”, 3
>
> This it means that your database has been “migrated” three times. The
> first time it apply “Migration 1” and “Migration 2”, the second time it
> apply “Migration 3” and the third time it apply “Migration 4” and
> “Migration 5”.
>
> I don’t know if it’s a suitable approach for your case. But it seems to me
> simple and effective.
>
> Ciao,
> Gianluca.
>
>
> On 23 Oct 2015, at 12:21, Daniel França <daniel.franca at gmail.com> wrote:
>
> Any idea?
>
> Em qui, 22 de out de 2015 às 13:30, Daniel França <daniel.franca at gmail.com>
> escreveu:
>
>> Hi guys,
>> I'm developing a single file ORM library for QML.
>> For now it's doing most of the main operations on tables.
>> You can see it here, with a basic documentation as well:
>> https://github.com/danielfranca/quickmodel
>>
>> But now I'm trying to implement a way to have migrations, and can't find
>> a good solution for that.
>>
>> I don't want anything complex, my goal will be to have something that you
>> simply change the table you want and increase the database version (then
>> the tables gonna be recreated and populated with existent data).
>>
>> I know about the changeVersion method on LocalStorage:
>> http://doc.qt.io/qt-5/qtquick-localstorage-qmlmodule.html
>>
>> But I'm not sure about how to use it.
>> i.e:
>> I call *openDatabaseSync *with version 1.0 and create my tables.
>> Then I change it to version 1.1 and call *changeVersion("1.0", "1.1")*
>>
>> But the next time my app runs it's not gonna open the database, instead
>> it'll give me an error "*Version mismatch*", because now the database
>> ini says that the database version is *1.1*, not *1.0.*
>>
>> And if I just change the open parameters to send *"1.1"*, it's not gonna
>> even open in the first run, giving the same error, because ini file will
>> say that the version is *1.0*, not *1.1.*
>>
>> To workaround this issue I'm just playing around with my own version
>> control, and ignoring the builtin QML solution.
>>
>> But it looks wrong =/
>> Probably I'm missing something and couldn't understand correctly.
>> Does anyone can help me find out a good solution?
>>
>> Best,
>> Daniel
>>
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