如何在Sangria中使用graphql查询过滤列表响应

import sangria.schema._
import sangria.macros.derive._

// 定义数据模型
case class Item(id: Int, name: String, category: String)

// 定义GraphQL Schema
val ItemType = deriveObjectType[Unit, Item]()
val QueryType = ObjectType("Query", fields[Unit, Unit](
  Field("items", ListType(ItemType),
    arguments = Argument("filter", OptionInputType(StringType)) :: Nil,
    resolve = ctx => {
      val filter = ctx.args.argOpt[String]("filter")
      // 根据过滤条件过滤数据
      val filteredItems = filter match {
        case Some(f) => items.filter(_.category == f)
        case None => items
      }
      filteredItems
    }
  )
))

val schema = Schema(QueryType)

// 执行GraphQL查询
val query = graphql"""
  query {
    items(filter: "category1") {
      id
      name
    }
  }
"""

val result = Executor.execute(schema, query)