如何在Rails的neo4j上使用LIKE“ =〜”？

Question

I'm using Neo4j with ruby on rails and I want to search user name with "LIKE" Operator "=~" .. with "Where" in ActiveNode to return a list of matched users. How can I do that?

Answer 1

Do it by using a string in where and then use a param for your regex. Once you start using a string in a where clause, you're operating in pure cypher, so http://docs.neo4j.org/chunked/milestone/query-where.html would be good to read.

Client.as(:c).where('c.name =~ {name}').params(name: '.h?ristopher')

If you want a shorter version, you can also do this:

Client.where(name: /.h?ristopher/)

The Cypher match it generates is nearly identical but that one won't use a param. It's less safe for your DB if you're basing your query off form data and your performance won't be as good due to the way Neo4j caches query paths.

Answer 2

The find_by method works like the where SQL query. Here is the documentation.

    Client.find_by user_name: 'Mr Smith'
    # => #<Client id: 1, user_name: "Mr Smith">

    Client.find_by user_name: 'non_user'
    # => nil