为什么graphQl在尝试切片查询时返回“Unknown argument 'first' on field...”错误？

Question

I am trying to fetch first five items of a set. My query is following:

query sequence($id: String) {
  sequence(id: $id) {
    items(first:1) {
            content
    }
  }
}

How ever, I get response

"Unknown argument \\"first\\" on field \\"items\\" of type \\"Sequence\\"."

As far as I understood from the docs this is how I am supposed to make query if I want to get a limited amount of items back.

Do I need to define the argument somewhere in the schema? How do I limit the amount of returned items properly?

Answer 1

All field arguments need to be defined in the schema, the default behaviour is for a field to accept no arguments.

You can define a first argument in your items field in your schema using syntax like this:

  type Sequence {
    items(first: Int): [Item]
  }

(See: Example No. 120 in the spec.)