我可以找到OrientDB中没有连接边的所有顶点吗？

Question

有没有一种简单的方法来查询群集中没有传入边的所有顶点？

Answer 1

这更完整，因为还涵盖了集合存在的情况，但它是空的：

select from the_cluster where in().size() = 0

Answer 2

Should it be this?

select from the_cluster where in_edgename is null

I know it's an old question but figured for anyone else who was wondering the same thing.

Answer 3

You can do something like this: for a vertex of a class say Vtex and the Edge of class say Edg

select from Vtex where in('Edg').size() =0

This will return all the vertices of Vtex class which have no incoming edge of type Edg.

Answer 4

下面的SQL似乎工作（如边缘存储领域in ，并out上顶点）：

select from the_cluster where in is null