Will apoc UUID's throw a constraint error?

[pererasys]

This is more of a theoretical question, but because of the way I'm doing things I think it may be relevant. Right now I've added a constraint on User.uuid, and when a user creates their account I'm adding a uuid property manually with apoc.create.uuid(). I know I can install it to the label, but I need that uuid returned from the query that created the user, so that doesn't work. My question is would it throw a constraint error because it might not be checking its uniqueness? I know it would be unlikely if possible, but I'd rather go with a solution where that won't happen

[Cobra]

Hello @pererasys and welcome to the Neo4j community,

Yeah it will throw a constraint error if you of course created the unique constraint:)

Doc: https://neo4j.com/docs/labs/apoc/current/graph-updates/uuid/

Regards,
Cobra

[pererasys]

Yea, I assumed so. Do you know of any way to create a new node with a unique uuid that can be accessed at creation? Because of the way the apoc plugin generates the uuid's, they aren't available until after the query is completed.

[Cobra]

Hello @pererasys,

Try something like SET p.pid = apoc.create.uuid() RETURN pid

If it's not working and you don't need to use the id for somthing else and you accept that the id will be reused when you will delete a node, you can do like this:

SET p.pid = id(p) RETURN pid

Regards,
Cobra

[pererasys]

Your first suggestion is what I'm currently doing, but this is what will throw the constraint error, and I can't use the node id because I'm using these id's across other databases. Is there no recommended solution for unique id's? Unless apoc.create.uuid() creates a unique value for the whole database as opposed to the label, in which case it should never throw a constraint error.

[Cobra]

Hello @pererasys,

You can manage ids by yourself and create a cypher request that will return you an unused id

Regards,
Cobra