neo4j-graphql-js：使用@cypher满足类型而不返回具体节点

问题描述

通常，我想创建一个GraphQL类型来表示跨越一个以上节点的Cypher查询的结果。在这种情况下，我无法从@cypher返回具体节点，因为不存在这样的节点。我试图从顶级@cypher查询中返回适当命名的字段，但是这种方法不起作用。

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
  }
}

我知道我可以使用每个字段@cypher的注释来满足各个字段的要求，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，那也可以，只要我可以在单个查询中收集满足该类型所需的数据即可。或者，如果这不可能，那也将是有用的信息。

解决方法

问题是，根据Person定义，查询输出处必须有一个对象。所以尝试这个查询

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