在neo4j .net客户端中使用cypher foreach

Question

I am using neo4j from C# with the Neo4jClient v 1.1.0.34 and would like to use foreach to update a value in multiple noted in C#, I have the following code:

graphClient.Cypher.Match("(u:User)-[:HAS_EMAIL]->(e:Email)-[:HAS_VER_CODE]->(s:VerCode)"
)
.Where((User u, Email e, VerCode s) => (
       u.id == user.id && e.address == email.address 
       && e.isVerified == false && s.expiry > DateTime.Now))
.Set("s.expiry = {now}")
.WithParam("now", DateTime.Now)
.ExecuteWithoutResults();

As is, the code above is not setting the expiry field on any of the matching nodes.

I need to set the expiry field to the current date time, but I cannot figure out how to use the .foreach (and have failed to find any examples in C#), the .for each template is give like this:

.foreach (var item in collection){}

Thank you for your time,

Adrian

Answer 1

Sorry - total misunderstanding of your question.

Using foreach in Cypher is different to foreach in C# , what you need is a collection of what you're wanting to search through, :

public class IdAndEmail { int Id {get;set;} string Address {get;set;} }

var idAndEmails = new List<IdAndEmail>{ new IdAndEmail { Id = 1, Address = "a@b.com"} /*etc*/ };

Once you have that, your cypher becomes:

graphClient.Cypher.Foreach(idAndEmails, "x")
    .Match("(u:User)-[:HAS_EMAIL]->(e:Email)-[:HAS_VER_CODE]->(s:VerCode)")
    .Where("u.id = x.Id AND e.address = x.Address")
    .AndWhere((Email e, VerCode s) => (e.isVerified == false && s.expiry > DateTime.Now))
    .Set("s.expiry = {now}")
    .WithParam("now", DateTime.Now)
    .ExecuteWithoutResults();

I'm not typing this somewhere I can fully test the code is right, in terms of syntax, but that should get you there.