Great Grandpa Query (yet another ancestor question)

[gor]

Scenario 1:

If I have a Great Grandpa ancestor (let's name him A); And my key is from "child1"; is there a way to check that my great grandpa is A? (hope I can do that without needing to loop)

Or can I check, if child1's key is of the path "A->B->C".

A -> B -> C -> (child1, child2...)

Scenario 2:

From the above. Great Grandpa has another descendants from "G", and would like to retrieve "H"s children:

A-> B -> C -> (children of C)

...-> G -> H -> (children of H)

I like to retrieve "H"s children, thinking that Grandpa knows the path from A, G, to H... can I do that? (hope I can do this in a query, without looping)

If you have a Go1 example: that would be awesome... 

Thanks Google! and I love you!

[timh]

Hi

Here is one approach you could use.

In each entity store a list of paths of each parent.  ie in second scenario

H has a list property called parent_paths it would have the following values ['/a/g','/a'] and its children would have ['/a','/a/g','/a/g/h'] etc

Then given any entity you can fetch all levels of descendants. So in your example  you just need to query for any entity

that has '/a/g/h'  in its parent_paths.  This doesn't allow you to restrict depth though.

Cheers

Tim

[gor]

the parent_path property could work. thanks.

[timh]

hi

If you store the depth of the path as an integer property of each child, you can then restrict you query by the depth below a parent as well.

Cheers

T

[gor]

right. thanks for the ideas.