如何将GraphQLObjectType与由带gql-tag的graphql-tag创建的模式组合在一起？

Question

我使用graphql-tag和apollo-server-express进行连接，为应用程序接口构建graphQL端点。目前，我创建的模式定义如下：

properties.js

let model = {}
const typeDefs = gql`
    extend type Query {
        property(id: Int!): [Property]
    }
    
    type Property {
        title: String
        street: String
        postalcode: String
        city: String
        country: String
    }
`
const resolvers = {
    Query: {
        property: getTheEntriesFromDB,
    },
}

model.typeDefs = typeDefs;
model.resolvers = resolvers;

module.exports = model;

和server.js

const server = new ApolloServer({
    modules: [
        require('./modules/properties'),
    ],
}):

然而，我想要基于数据库模式自动创建类型'Property‘。我发现我可以像这样创建一个GraphQLObjectType：

const propertyType = new graphql.GraphQLObjectType({
    name: 'Property',
    fields: {
        title: { type: graphql.GraphQLString },
        street: { type: graphql.GraphQLString },
        postalcode: { type: graphql.GraphQLString },
        city: { type: graphql.GraphQLString },
        country: { type: graphql.GraphQLString },
    }
});

但我不知道如何将它与

let model = {}
const typeDefs = gql`
    extend type Query {
        property(id: Int!): [Property]
    }
`
const resolvers = {
    Query: {
        property: getTheEntriesFromDB,
    },
}

model.typeDefs = typeDefs;
model.resolvers = resolvers;

module.exports = model;

来创建最终的模式。谁能给我指个方向？任何帮助都是非常感谢的。提前谢谢你！

Answer 1

好的，经过几个小时的试错和搜索，我找到了这个对我有效的解决方案：

properties.js

const { buildASTSchema, GraphQLObjectType, GraphQLSchema, GraphQLString, parse, printSchema } = require('graphql')

let model = {}

const propertyType = new GraphQLObjectType({
    name: 'Property',
    fields: {
        title: { type: GraphQLString },
        street: { type: GraphQLString },
        postalcode: { type: GraphQLString },
        city: { type: GraphQLString },
        country: { type: GraphQLString },
    }
});

let typeDefs = gql`
    extend type Query {
        property(id: Int!): [Property]
    }
    
    type Property {
        id: Int
    }
`

typeDefs.definitions[0].kind = 'ObjectTypeDefinition' //replace ObjectTypeExtension with ObjectTypeDefinition to make AST 'valid' but keep extend in gql-tag to satisfy code inspection in ide
typeDefs = parse(printSchema(buildASTSchema(typeDefs)).replace('type Query {', 'extend type Query {') + printSchema(new GraphQLSchema({ types: [ propertyType ]})).replace('type Property {', 'extend type Property {'))

const resolvers = {
    Query: {
        property: getTheEntriesFromDB,
    },
}

model.typeDefs = typeDefs;
model.resolvers = resolvers;

module.exports = model;

“扩展”关键字是必需的，因为属性需要在gql标记内声明，而查询在整个项目中声明了不止一次。