GraphQL 解析 GraphQLObjectType

Posted 2023-03-08

【中文标题】GraphQL 解析 GraphQLObjectType

【英文标题】：GraphQL resolve GraphQLObjectType

【发布时间】：2017-09-19 13:52:55

【问题描述】：

我正在使用express-graphql 以及以下查询：

invitations 
    sent 
    received

架构定义（简化）如下：

const InvitationType = new GraphQLObjectType(
    name: 'InvitationType',
    description: 'Friends invitations',
    fields: 
        sent: 
            type: new GraphQLList(GraphQLString),
            description: 'Invitations sent to friends.',
            resolve() 
             return ['sentA'];
            
        ,
        received: 
            type: new GraphQLList(GraphQLString),
            description: 'Invitations received from friends.',
            resolve() 
             return ['receivedA', 'receivedB'];
            
        
    
);

// Root schema
const schema = new GraphQLSchema(
    query: new GraphQLObjectType(
      name: 'RootQueryType',
      fields: 
          invitations: 
              type: InvitationType // no resolve() method here.
          
      
    )
);

但是，resolve 方法永远不会为 sent 和 received 字段调用。上面的查询返回：

data: invitations: sent: null, received: null

有没有办法解决嵌套字段（sent 和 received）而不在父字段（invitations）上定义 resolve() 方法？

【参考方案1】：

这对我有用！根据GraphQL Documentation，如果resolve方法返回一个非标量，执行将继续。所以下面的代码有效：

// Root schema
const schema = new GraphQLSchema(
    query: new GraphQLObjectType(
      name: 'RootQueryType',
      fields: 
        invitations: 
          type: InvitationType,
          resolve: () => () // Resolve returns an object.
        
      
    )
);

希望这会有所帮助。干杯！