On 2017-10-04 13:57, Nikita Timofeev <[email protected]> wrote:
> ObjectSelect.columnQuery can select individual columns, as it was
> designed just for that.
> However you can also use it to get full entities along with some
> arbitrary properties (aggregates, dependent objects, etc.).
> In your case you created property with type of "Cargo" and it returns
> you collection of Cargo objects.
> Just use correct type of required column (String, Integer, etc.).
>
> However easiest (and also safe) way to use it is via static Properties
> generated in a superclass of your entity, i.e. something like this:
>
> List<String> someStringProperties =
> ObjectSelect.columnQuery(Cargo.class,
> Cargo.SOME_STRING_PROPERTY).select(ctx);
>
>
> On Wed, Oct 4, 2017 at 12:45 PM, [email protected] <[email protected]> wrote:
> > Should ObjectSelect.columnQuery execute a SQL query with just one column
> > selected?
> >
> > I am using Cayenne 4.1 but running this code:
> >
> > Property<Cargo> property1 = Property.create("area", Cargo.class);
> >
> > List<Cargo> select =
> > ObjectSelect.columnQuery(Cargo.class,property1).where(Expression.fromString("area>10")).select(ctx);
> >
> > the query executed select all the columns of cargo table.
> >
> > I need to specify which columns the queries must return because I have
> > tables with hundreds of columns that I do not need, returning all the
> > columns every time is very time consuming.
> >
> > Andrea
>
>
>
> --
> Best regards,
> Nikita Timofeev
But if I do something like this:
Property<String> property1 = Property.create("area", String.class);
Property<Double> property2 = Property.create("voyage.flCost", Double.class);
List<Object[]> select =
ObjectSelect.query(Cargo.class).columns(property1,property2).select(ctx);
There is the possibility to get a list of Cargo objects?
