Hey guys,

I need your help. I´ve got a problem, that really freak me out.

I have two DataObjects: "Page" and "Book". One "Book" has many "Pages".
The "Book" have a variable called "Active".

Now I want to get the IDs from "Page", but only from the pages which has an "active" Book.
So I need something like this:

SELECT Page.ID FROM Page
LEFT JOIN Book ON Page.BookID = Book.ID
  WHERE Book.Active = 1

Now have tried to

$sqlQuery = new SQLQuery();
$sqlQuery->setFrom("Page");
$sqlQuery->selectField("Page.ID", "ID");
$sqlQuery->addLeftJoin('Book','"Page.BookID" = "Book.ID"');
$sqlQuery->addWhere(' "Book.Active"=1 ');

But with this code, I get the error "Unknown column Book.Active". Any idea, how to fix this?

You should be able to do:

Page::get()->filter('Book.Active', true)->column('ID');

GREAT! It works, thanks!
So easy and simple.