Sort of, GraphQL is just an interface that describes your data models, but you need to implement "resolvers" for each operation that tells the server how to fetch/mutate the queried data.

So you might have a GQL type like:

    type User {
      name: String
      age: Int
    }

But you need to implement a query with business logic for fetching this data, and that can be anything (but generally, a DB call).

Projects like Hasura kind of blur this line, as it's essentially one big GQL -> SQL JIT compiler in Haskell though.