为啥我的 Graphql 查询返回 null？ [复制]

Posted 2023-03-08

【中文标题】为啥我的 Graphql 查询返回 null？ [复制]

【英文标题】：Why is my Graphql query returning null? [duplicate]为什么我的 Graphql 查询返回 null？ [复制]

【发布时间】：2018-04-13 03:09:26

【问题描述】：

我正在尝试为所有人设置一个 graphql 应用程序，以便轻松访问来自 games.espn.com 的数据，但我遇到了查询返回 null 的问题。我想知道我是否可能在某处错过了返回或解析功能？我已经搜索这段代码几天了，似乎无法弄清楚为什么它没有返回值。

这是我的 schema.js 文件：

const 
  GraphQLObjectType,
  GraphQLString,
  GraphQLInt,
  GraphQLSchema,
  GraphQLList,
  GraphQLNonNull,
  GraphQLBoolean,
  GraphQLFloat
 = require('graphql');
const axios = require('axios');
const request = require('request');

const PlayerType = new GraphQLObjectType(
  name: 'Player',
  fields:() => (
    droppable: type:GraphQLBoolean,
    percentStarted: type:GraphQLFloat,
    jersey: type:GraphQLString,
    playerRatingSeason: type:GraphQLFloat,
    isIREligible: type:GraphQLBoolean,
    draftRank: type:GraphQLInt,
    universeId: type:GraphQLInt,
    firstName: type:GraphQLString,
    lastName: type:GraphQLString,
    sportsId: type:GraphQLInt,
    healthStatus: type:GraphQLInt,
    percentOwned: type:GraphQLFloat,
    proTeamId: type:GraphQLInt,
    tickerId: type:GraphQLInt,
    isActive: type:GraphQLBoolean,
    playerId: type:GraphQLInt,
    percentChange: type:GraphQLFloat,
    defaultPositionId: type: GraphQLInt,
    totalPoints: type:GraphQLFloat,
  )
);


const CurrentPeriodProjectedStatsType = new GraphQLObjectType(
  name: 'CurrentPeriodProjectedStats',
  fields:() => (
   appliedProjectedStatTotal: type:GraphQLFloat
  )
);


const CurrentPeriodRealStatsType = new GraphQLObjectType(
  name: 'CurrentPeriodRealStats',
  fields:() => (
    appliedRealStatTotal: type:GraphQLFloat
  )
);



const PlayerSlotType = new GraphQLObjectType(
  name: 'PlayerSlot',
  fields:() => (
    pvoRank: type:GraphQLInt,
    player: 
      type: PlayerType
    ,
    watchList: type:GraphQLBoolean,
    isKeeper: type:GraphQLBoolean,
    isTradeLocked: type:GraphQLBoolean,
    currentPeriodProjectedStats: 
      type: CurrentPeriodProjectedStatsType
    ,
    opponentProTeamId: type:GraphQLInt,
    slotCategoryId: type:GraphQLInt,
    lockStatus: type:GraphQLInt,
    isQueuedWaiverLocked: type:GraphQLBoolean,
    currentPeriodRealStats: 
      type: CurrentPeriodRealStatsType
    
  )
);


const SlotsType = new GraphQLObjectType(
  name: 'Slots',
  fields:() => (
    player0: 
      type: PlayerSlotType
    ,
    player1: 
      type: PlayerSlotType
    ,
    player2: 
      type: PlayerSlotType
    ,
    player3: 
      type: PlayerSlotType
    ,
    player4: 
      type: PlayerSlotType
    ,
    player5: 
      type: PlayerSlotType
    ,
    player6: 
      type: PlayerSlotType
    ,
    player7: 
      type: PlayerSlotType
    ,
    player8: 
      type: PlayerSlotType
    ,
    player9: 
      type: PlayerSlotType
    ,
    player10: 
      type: PlayerSlotType
    ,
    player11: 
      type: PlayerSlotType
    ,
    player12: 
      type: PlayerSlotType
    ,
    player13: 
      type: PlayerSlotType
    ,
    player14: 
      type: PlayerSlotType
    ,
    player15: 
      type: PlayerSlotType
    ,
  )
);


const DivisionType = new GraphQLObjectType(
  name: 'Division',
  fields:() => (
    divisionName: type:GraphQLString,
    divisionId: type:GraphQLInt,
    size: type:GraphQLInt
  )
);


const TeamType = new GraphQLObjectType(
    name: 'Team',
    fields:() => (
      divisionStanding: type:GraphQLInt,
      overallStanding: type:GraphQLInt,
      waiverRank: type:GraphQLInt,
      division: 
        type: DivisionType
      ,
      teamAbbrev: type:GraphQLString,
      teamNickname: type:GraphQLString,
      logoUrl: type:GraphQLString,
      teamLocation: type:GraphQLString,
      teamId: type:GraphQLInt,
      logoType: type:GraphQLString
    )
);



const List0Type = new GraphQLObjectType(
  name: 'List0',
  fields: () => (
    slots: 
      type: SlotsType
    ,
    team: 
      type: TeamType
    ,
    teamId: type: GraphQLInt,
    appliedActiveProjectedTotal: type: GraphQLFloat,
    appliedInactiveProjectedTotal: type: GraphQLFloat,
    appliedActiveRealTotal: type: GraphQLFloat,
    appliedInactiveRealTotal: type: GraphQLFloat,
  )
);


const TeamsType = new GraphQLObjectType(
  name: 'Teams',
  fields: () => (
    list0: 
      type: List0Type
    ,
    list1: 
      type: List0Type
    
  )
);


// need to define each type individually, working from the bottom up and creating types as needed
const BoxscoreType = new GraphQLObjectType(
  name: 'Boxscore',
  fields: () => (
    teams: 
      type: TeamsType,
      /*resolve(boxscore)
        return boxscore.teams;
      */
    ,
    scoringPeriodId: 
      type: GraphQLInt,
    ,
    matchupPeriodId: 
      type: GraphQLInt,
    ,
    homeTeamBonus: 
      type: GraphQLInt,
    

  )
);

const MetadataType = new GraphQLObjectType(
  name: 'metadata',
  fields: 
    leagueId: type: GraphQLString,
    status: type: GraphQLString,
    dateModifiedLeague: type: GraphQLString,
    seasonId: type: GraphQLString,
  
);

const BoxscoreDataType = new GraphQLObjectType(
  name: 'BoxscoreData',
  fields: 
    boxscore: type:BoxscoreType,
    metadata: type:MetadataType,
  ,
);

const EspnQuery = new GraphQLObjectType(
    name: 'EspnQuery',
    fields: 
      getBoxscore: 
        type: BoxscoreDataType,
        args: 
          leagueId: 
            name: 'leagueId',
            type: new GraphQLNonNull(GraphQLInt)
          ,
          seasonId: 
            name: 'seasonId',
            type: new GraphQLNonNull(GraphQLInt)
          ,
          teamId: 
            name: 'teamId',
            type: new GraphQLNonNull(GraphQLInt)
          ,
          scoringPeriodId: 
            name: 'scoringPeriodId',
            type: new GraphQLNonNull(GraphQLInt)
          ,
        ,
        resolve: (obj, leagueId, seasonId, teamId, scoringPeriodId) => 
            const url = 'http://games.espn.com/ffl/api/v2/boxscore?leagueId=1150587&seasonId=2017&teamId=5&scoringPeriodId=7'
            //const url = 'http://games.espn.com/ffl/api/v2/boxscore?leagueId='+ leagueId + '&seasonId=' + seasonId + '&teamId=' + teamId + '&scoringPeriodId=' + scoringPeriodId
            //console.log('leagueId is: ' + leagueId + 'seasonId is: '+seasonId+'teamId is: '+teamId+'scoringPeriodId is: '+scoringPeriodId);

            return axios(url)
              .then(res => res.data);


        
      
    ,
  );

// Keep at the bottom //
module.exports = new GraphQLSchema(
  query: EspnQuery
);

我在 Graphiql 中运行的查询是：

    getBoxscore(leagueId: 1150587, seasonId: 2017, teamId: 5, scoringPeriodId: 7) 
        boxscore
        teams 
            list0
          slots
            player0
              player
                firstName
              
            
          
        
       
      
    

不幸的是，它正在回归：

  "data": 
    "getBoxscore": 
      "boxscore": 
        "teams": 
          "list0": null
        
      
    
  

【问题讨论】：

您有一个庞大的架构，您正试图将它们组合在一起。如果您添加了graphql-tools 包并使用了makeExecutableSchema，那么编写、阅读和排除故障可能会少很多痛苦。你可以阅读更多here。

【参考方案1】：

您的架构结构与数据结构不匹配。无论何时返回一个数组，您都应该使用GraphQLList——不需要您添加的ListType。

例如，如果您查看端点返回的 JSON，teams 是一个数组，而不是一个对象。您已经创建了一个与团队数据结构匹配的 TeamType，但我们需要告诉 GraphQL teams 将是一个 TeamType 对象的列表（数组），而不仅仅是一个对象。所以我们写：

teams:  type: new GraphQLList(TeamsType) 

用 GraphQL 模式语言编写，即 [TeamsType]。 TeamsType 中的大多数字段都是对象或标量。但是，slots 也是一个数组，因此您可以类似地编写：

slots:  type: new GraphQLList(SlotsType) 

等等。