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neo4jcypherneo4jclient

Return result base on query result

I'm making an application which use neo4j as my back-end db. I have this class :

class Person
{
public string Id{get;set;}
public string Name{get;set;}
}

I want to create a query that return 0 when person.Id exists in db (that means there can't be users with the same id exist in db together) and 1 when person.Id doesn't exist.

Can anyone help me please ?

Thank you,

P/S:

Neo4jClient or Neo4j query is OK .

I can convert Neo4j query to Neo4jClient in .Net

Solution

  • You can use combination of OPTIONAL MATCH and CASE:

    OPTIONAL MATCH (P:Person {Id:123})
RETURN CASE P WHEN NULL THEN 1 ELSE 0 END

    Also You can specify unique constraints that guarantee uniqueness of a certain property on nodes with a specific label:

    CREATE CONSTRAINT ON (P:Person) ASSERT P.Id IS UNIQUE