Ne4j-graphql-js:使用@cypher满足类型，而不返回具体节点

Question

我经常希望创建一个GraphQL类型来表示跨越多个节点的Cypher查询的结果。在这种情况下，我不能从@cypher返回具体的节点，因为不存在这样的节点。我试图从一个顶级@cypher查询返回适当命名的字段，但这种方法不起作用。

import { makeAugmentedSchema, neo4jgraphql } from 'neo4j-graphql-js';
import { ApolloServer } from 'apollo-server';
import neo4j from 'neo4j-driver';

const typeDefs = `
type Person {
    name: String
    age: Int
}

type Query {
    persons: [Person] @cypher(
        statement: """
            WITH [["foo", 42], ["bar", 43]] AS x UNWIND x AS y
            RETURN y[0] AS name, y[1] AS age
        """
    )
}
`;

const driver = neo4j.driver(
    'bolt://localhost:7687',
    neo4j.auth.basic('neo4j', 'password')
);


const resolvers = {
};

const schema = makeAugmentedSchema({ typeDefs, resolvers });


const server = new ApolloServer(
    {
        schema,
        resolvers,
        context: {driver}
    }
)


server.listen(4000, '0.0.0.0').then(({ url }) => {
    console.log(`GraphQL API ready at ${url}`);
});

查询：

{
  persons {
    name
    age
  }
}

产生以下错误：

{
  "errors": [
    {
      "message": "String(\"foo\") (of class org.neo4j.values.storable.StringWrappingStringValue)",
      "locations": [
        {
          "line": 2,
          "column": 3
        }
      ],
      "path": [
        "persons"
      ],
      "extensions": {
        "code": "INTERNAL_SERVER_ERROR",
        "exception": {
          "code": "Neo.DatabaseError.General.UnknownError",
          "name": "Neo4jError",
          "stacktrace": [
            "Neo4jError: String(\"foo\") (of class org.neo4j.values.storable.StringWrappingStringValue)",
            "",
            "    at captureStacktrace (/home/amoe/dev/neo4j-graphql-js-return-aggregate-type/node_modules/neo4j-driver/lib/result.js:277:15)",
            "    at new Result (/home/amoe/dev/neo4j-graphql-js-return-aggregate-type/node_modules/neo4j-driver/lib/result.js:68:19)",
            "    at newCompletedResult (/home/amoe/dev/neo4j-graphql-js-return-aggregate-type/node_modules/neo4j-driver/lib/transaction.js:449:10)",
            "    at Object.run (/home/amoe/dev/neo4j-graphql-js-return-aggregate-type/node_modules/neo4j-driver/lib/transaction.js:287:14)",
            "    at Transaction.run (/home/amoe/dev/neo4j-graphql-js-return-aggregate-type/node_modules/neo4j-driver/lib/transaction.js:123:32)",
            "    at _callee2$ (/home/amoe/dev/neo4j-graphql-js-return-aggregate-type/node_modules/neo4j-graphql-js/dist/index.js:222:35)",
            "    at tryCatch (/home/amoe/dev/neo4j-graphql-js-return-aggregate-type/node_modules/regenerator-runtime/runtime.js:63:40)",
            "    at Generator.invoke [as _invoke] (/home/amoe/dev/neo4j-graphql-js-return-aggregate-type/node_modules/regenerator-runtime/runtime.js:293:22)",
            "    at Generator.next (/home/amoe/dev/neo4j-graphql-js-return-aggregate-type/node_modules/regenerator-runtime/runtime.js:118:21)",
            "    at asyncGeneratorStep (/home/amoe/dev/neo4j-graphql-js-return-aggregate-type/node_modules/@babel/runtime-corejs2/helpers/asyncToGenerator.js:5:24)"
          ]
        }
      }
    }
  ],
  "data": {
    "persons": null
  }
}

我知道我可以用每个字段的@cypher注释来满足各个字段，但这不适用于这种情况。这个问题是关于满足整个结果类型的。

如果答案需要在resolvers数组中使用自定义处理程序，也可以，只要我可以收集满足单个查询中的类型所需的数据。或者，如果这是不可能的，那也是有用的信息。

Answer 1

问题在于，根据Person定义，查询输出处必须有一个对象。因此，请尝试以下查询

WITH [["foo", 42], ["bar", 43]] AS x UNWIND x AS y
RETURN { name: y[0], age: y[1] } as Person