DateTime comparison in WHERE condition

Hello, I’m trying to use Neo4jClient to implement a few basic queries and some obstacles came along when I tried to query Neo4j datetime properties with .NET datetime objects. Let’s assume I have the following model:

    public class Something
    {
        [Neo4jDateTime]
        [JsonProperty("arrival_date_time")]
        public DateTime Arrival { get; set; }

        [Neo4jDateTime]
        [JsonProperty("departure_date_time")]
        public DateTime Departure { get; set; }
    }

…and the following query:

DateTime arrival = DateTime.Parse("2019-03-22T10:00:00");
var query = client.Cypher
    .Match($"(thing:{typeof(Something).Name})")
    .Where((Something thing) => thing.Arrival > arrival)
    .Return<Something>("thing");

This produces the following Neo4j query:

MATCH (thing:Something)
WHERE (thing.arrival_date_time > "2019-03-22T10:00:00")
RETURN thing

…which seems to be incorrect as in order to get the correct result, the query parameter should be parsed to Neo4j DateTime object, as below:

MATCH (thing:Something)
WHERE (thing.arrival_date_time > datetime("2019-03-22T10:00:00"))
RETURN thing

Am I doing something wrong or is it a bug?

[cskardon]

Hmm not entirely true - adding the [Neo4jDateTime] attribute to a property which is a DateTime will serialize it as a Neo4j DateTime.

The problem is how the Where knows this. Solution wise - I’m not sure how you would fix it - my gut feeling is that you either have a global setting which then treats all DateTime instances as one or the other. When you pass in a parameter it doesn’t know there is an attribute.

I guess maybe an overload to AddParam which let’s you say it should be a Neo4j datetime would be the quickest route - does force you into a .WithParam scenario though

[Clooney24]

I don’t think this is a bug it’s just not yet supported. C# DateTime is serialized to a Neo4j string property in the format “2020-03-09T16:45:00.9199162+01:00” and back from string to C# DateTime. The neo4j temporal types and features which where introduced end of 2018 are not yet supported, see Issue #291