Generic interface for Marshal/Factory like RowMapper

It is convenient to have RowMapper<T>, because it lets you create generic code that reads from a database (e.g. a helper function that reads all rows into a List<T>, a GUI to display things, etc.).

It would be great to have the same generic interface for the “write” direction, i.e. for the Marshal and/or the Factory.

It could look something like this:

interface MarshalInterface<T> {
    ContentValues asContentValues();
}
interface FactoryInterface<T> {
    MarshalInterface<T> marshal();
    MarshalInterface<T> marshal(T copy);
    RowMapper<T> select_allMapper();
}

and would be usable like this:

class Inserter<T> {
    SQLiteOpenHelper openHelper;
    FactoryInterface<T> factory;
    String tableName;
    public void insert(T item) {
        db.insert(tableName, null, factory.marshal(item).asContentValues();
    }
}

[Philipp91]

a .bind(@NonNull FooModel object) could be generated which would use the getter methods of the interface to fill in the insert or update call

INSERT INTO users VALUES ?;

+1 on these. Can I help implement that?

Related/duplicate: https://github.com/square/sqldelight/issues/572

[yasirmhd]

We use content providers for all our DB operations. We use the SQLDelight created models on top of the cursors in the UX code. We would also like to use this for persisting the data into the Content Provider.

To do that we will need to get the content values. If this is exposed then it will be helpful for the application code to work with content providers as well instead of working directly with the DB (multiple rows to be inserted/updated along with transaction support).