How to check if an array property contains a certain value?

March 1, 2023

I have a graph with two vertices, and each contain a property named interests, which is an array of strings. I wanted to compare how many strings both arrays have in common and also if the array contains a certain string.

I have tried the following query, but it throws an error:

SELECT * FROM cypher('QuirkyMatch', $$
        MATCH (v:Person), (user:Person)
        WHERE user.name = 'Sarah' AND v.age > (user.age + 1) AND v.interests CONTAINS 'Art'
        RETURN v
$$) as (potential_match agtype);

ERROR:  agtype string values expected

Here is how I created them:

SELECT * FROM cypher('QuirkyMatch', $$
    CREATE (:Person {
        name: 'Alex',
        age: 27,
        occupation: 'Graphic Designer',
        interests: ['Art', 'Photography', 'Traveling', 'Indies Music'],
        weird_fact: 'I can hold up to 400 straws in my mouth. LOL.'
    }), 
    (:Person {
        name: 'Sarah',
        age: 25,
        occupation: 'Software Engineer',
        interests: ['Hiking', 'Board Games', 'Sci-Fi Movies', 'Dungeons & Dragons', 'Painting', 'Art'],
        weird_fact: 'I collect hot sauces and I have over 50 different ones :)'
    })
$$) as (v agtype);

>Solution :

The CONTAINS keyword is not valid for checking if an element exists in an array in Cypher. Instead, try using the IN keyword. Here’s an updated query that should work:

SELECT * FROM cypher('QuirkyMatch', $$
    MATCH (v:Person), (user:Person)
    WHERE user.name = 'Sarah' AND v.age > (user.age + 1) AND 'Art' IN v.interests
    RETURN v
$$) as (potential_match agtype);