SqlModels: QSqlTableModel's that are created entirely from QML

Leei

Github link
This project currently contains two SQL Models.

The first one is called SqlModel, which is a subclass of QSqlTableModel that can create a SQL database, and query against it, all from QML. This model lives on the UI thread.

The second model included in this project is called SqlThreadedModel. This is a subclass of QAbstractTableModel, which serves as a proxy model for an internal SqlModel. The Internal SqlModel lives in its own thread, separate from the UI thread, and so will not hang the UI thread if queries take a long time. The SqlThreadedModel will listen to the
SqlModel's signals and will update accordingly.

This project was made for another one of my projects, but I made them as QML plugins, so more people could get the benefit of using them. If you have any questions or suggestions please feel free!

SGaist

Hi and welcome to devnet,

Thanks for sharing !

Did you also plan to use it with other database system like PostgreSQL ?

Leei

@SGaist Well I haven't tested it with any other SQL driver, but there is a property for changing that, located here, it defaults to QSQLITE. I only have experience with SQLite, but the queries being made on the database are standard ones.

If someone has an interest in using it for PostgreSQL, and I do not support a feature, I will surely add it in.

Thank you for the welcome! :)

SGaist

The problem I see with that property as string is that you can change the database type but you can't give settings like user name and password.

Leei

@SGaist Ahh, good catch. I can easily add in some more Q_PROPERTY's to allow users to edit those settings, user name and password are just something I don't use, so they weren't initially included. The QSqlDatabase isn't formed until the Component.onCompleted signal is emitted, so any of the database features can be added in.

SGaist

Rather than have a property per QSqlDatabase property, I'd go with a small class that contains them so you can re-use it easily for all database backends. That will also make the QML code clearer.

Leei

@SGaist That is exactly what I did! There is a new grouped property called "sqlDatabase". All the database settings are housed in a Database class. Defining the settings looks like:

SqlModel {
  id:  sqlModel;

  sqlDatabase {
    userName: "Fred"
    password: "123ABC"
    numericalPrecisionPolicy: Database.HighPrecision
    port: 192 // Anything except INT_MIN
    connectionName: "FRED_DB"
    // ...
  }

}

SGaist

Nice ! What about dbSettings or dbParameters ? It might make it clearer that you are not instantiating a database but just providing information to set things up.

Leei

@SGaist Very true. I changed the name to "databaseSettings". Thanks for the input!

SGaist

You're welcome !

Did you consider to submit your work for inclusion in Qt ?

Leei

@SGaist I did actually! What's the process to go about doing this?

SGaist

Good !

Take a look at the Gerrit introduction wiki page to get started.

The module that looks the most suitable (to me) is QtDeclarative. You'll have to refactor your code a bit to follow Qt's coding style guide and naming convention.

Leei

@SGaist I don't mind refactoring it, it's not very long. I will definitely look into this. Thanks!