如果使用列，如何获取联接数据？

Question

I have two tables, ProductGroup and ProductGroupTranslation which are joined together.

In ProductGroup I have id and in translation table I have title.

Now I want to get all ProductGroups:

$categories = ProductGroup::find(array(
    "product_group_id IS NULL",
    "order" => "id DESC"
) );

This works and I can access translation via $categories->productgrouptranslation->getTitle();

But how do I access joined table if I fetch only columns out:

$categories = ProductGroup::find(array(
   "columns" => "id",
    "product_group_id IS NULL",
    "order" => "id DESC"
) );

Answer 1

This is a limitation of the technology you are using. If you specify the columns you want to retrieve data from, then those are the only columns you are going to have access to.

If you are asking "what columns do I need to specify to only get the id and title out of a joined result set", then I suspect the answer is to pass an array of columns into columns with the column name preceded with the table name:

$categories = ProductGroup::find(array(
   "columns" => "ProductGroup.id,ProductGroupTranslation.title",
   "product_group_id IS NULL",
   "order" => "id DESC"
) );

Replace the above table names with the actual table names.