删除旧关系并在带有cypher的c＃上的同一个查询中为Neo4j DB创建具有相同标签的新关系

Question

Let's suppose Location and Entity nodes.

I want in the same cypher query to delete all relationships (location)<-[:HAS]-() and (location)<-[:HAS]-(entity) inserts new ones.

Basically I had tried this query:

public void UpdateRelationshipOfLocation<T>(Location entityGiven, int geoNameId) where T : class, new()
        {
            var type = typeof(T).Name;

            var client = Graph.GetClient();

            client.Cypher
                .Match("location:Location")
                .Where((Location location) => location.GeoNameId == entityGiven.GeoNameId)
                .With("location")
                .Match("(location)<-[rel:HAS]-()")
                .Delete("rel")
                .With("location")
                .Match("(entity:" + type + ")")
                .Where((Admin entity) => entity.GeoNameId == geoNameId)
                .Create("(location)<-[:HAS]-(entity)")
                .ExecuteWithoutResults();
        }

Parameters passed to the query: location and geoNameId to find entity.

However, it results with no new relationships added. And no relationships deleted aswell.

Any way to do it in the same query?

I already got the query in Cypher can someone help me to translate do c# language?

MATCH (l:Location {GeoNameId: 9410021})
OPTIONAL MATCH ()-[r:HAS]->(l)
DELETE r
WITH l
MATCH (a:Admin2 {GeoNameId:  2367567})
MERGE (a)-[:HAS]->(l);

Answer 1

You seem to be missing parentheses around your first Match call - should be something akin to this I think:

public void UpdateRelationshipOfLocation<T>(Location entityGiven, int geoNameId) where T : class, new()
        {
            var type = typeof(T).Name;

            var client = Graph.GetClient();

            client.Cypher
                .Match("(location:Location)") // Note parens added
                .Where((Location location) => location.GeoNameId == entityGiven.GeoNameId)
                .With("location")
                .Match("(location)<-[rel:HAS]-()")
                .Delete("rel")
                .With("location")
                .Match("(entity:" + type + ")")
                .Where((Admin entity) => entity.GeoNameId == geoNameId)
                .Create("(location)<-[:HAS]-(entity)")
                .ExecuteWithoutResults();
        }

Am assuming it's related to a similar issue you posted in this question