Why is the direction wrong at all? Based on relationships between entities they would automatically be added correctly.

What I did it was a simple example. Just to get the idea.

For instance, if I choose first the ClientInvoice and then the Client, what will happen is that it will do the join like ClientInvoice With of Without Client.

My idea is more for when we have a lot of entities. On those situation might be helpfull. The user might have wrong results due to the joins direction and need to switch them.

I see another benefit of this feature apart from Idea suggested.

In particular above scenario where with or with out. This is nothing but left outer join.

In case if I feel like to make a right outer join then I need to change place of entities by selecting those. So the swap will save those efforts.

Alternative to this feature is to introduce 'reverse with our with out' or something like that.

But certainly swapping will help toggle left/right joins faster