CODEWITHSUNDEEP
neo4j
HanXu
HanXu

Reputation: 5597

How to fetch nodes with different labels in one query in Neo4j

I have three types of nodes:

(:Meal), (:User), (:Dish)

With relationships:

(:Meal)<-[:JOIN]-(:User), (:Meal)<-[:ORDERED]-(:Dish)

Now I want to fetch the information of meal in one query. I want to get result like this:

id: 1
name: xxx,
users: [1,2,3,4],
dishes: [23,42,42]

where users and dishes fields contains the ids of those users and dishes.

I tried:

MATCH (meal:Meal)
OPTIONAL MATCH (meal)<-[:JOIN]-(user:User)
OPTIONAL MATCH (meal)<-[:ORDERED]-(dish:Dish)
RETURN id(meal), meal.name, COLLECT(ID(user)), COLLECT(ID(dish))

However, this query will generate a lot duplication of users and dishes. If there are N users and M dishes, it will match N*M user-dish pairs.

I do realize that I can use DISTINCT to remove duplication. However, I am not sure about the efficiency of such query.

Is there any better way?

Upvotes: 2

Views: 122

Answers (1)

Stefan Armbruster
Stefan Armbruster

Reputation: 39925

Try to separate the different parts of your query using WITH:

MATCH (meal:Meal)
OPTIONAL MATCH (meal)<-[:JOIN]-(user:User)
WITH meal, collect(ID(user)) as users
OPTIONAL MATCH (meal)<-[:ORDERED]-(dish:Dish)
RETURN id(meal), meal.name, users, COLLECT(ID(dish)) as dishes

Upvotes: 2

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