filtering edge by property during traverse

[john davids]

Hello,

I'm new to OrientDB. 

I have a simple OrientDB database with Classes and one type of relationship between them. 

Even if is one type of Edge we decided to use a 'type' attribute for the Edge that differentiates between them.

Class0 --has a--> Class1

Class1 --has a--> Class2

Class1 --is a--> Class3

I'm interested to start traversing the graph from Class0 vertex (with id #12:7), but only following the relations that have the 'type' attribute 'has a'.

So the result should be Class0, Class1, Class2

I'm not managing to find a correct 'while' clause...

Something like this is obviously not ok

traverse outE(), out() from #12:7 while (@class = 'Class' or (@class = 'Relation' and outE().type = 'has a'))

Any hints for me pls?

Thank you!

[john davids]

I found a solution and seems to be working. Could you please validate it? I'm afraid not to fool myself with the solution

select from (traverse * from #12:7 while (type= 'type of' or type is null))

The type is null clause is put because the vertices don't have the type property.