Graphql：没有为 Go 中的突变配置模式答案

【问题标题】：Graphql : Schema is not configured for mutations in GoGraphql：没有为 Go 中的突变配置模式
【发布时间】：2020-11-24 11:29:51
【问题描述】：

我正在尝试在Go 中写入Graphql Mutation。我正在使用github.com/graphql-go/graphql 库。

这是我为此编写的代码。

package main

import (
  "bytes"
  "encoding/json"
  "fmt"
  "io/ioutil"
  "net/http"

  "github.com/graphql-go/graphql"
)

type userMaster struct {
  Name string `json:"userName"`
  ID   string `json:"emailID"`
}

var user userMaster

func main() {
fmt.Println("Hello world !!!")

userType := graphql.NewObject(
    graphql.ObjectConfig{
        Name: "userMaster",
        Fields: graphql.Fields{
            "userName": &graphql.Field{
                Type: graphql.String,
            },
            "emailID": &graphql.Field{
                Type: graphql.String,
            },
        },
    },
)

rootMutation := graphql.NewObject(graphql.ObjectConfig{
    Name: "Mutations",
    Fields: graphql.Fields{
        "createUser": &graphql.Field{
            Type: userType,
            Args: graphql.FieldConfigArgument{
                "userName": &graphql.ArgumentConfig{
                    Type: graphql.NewNonNull(graphql.String),
                },
                "emailID": &graphql.ArgumentConfig{
                    Type: graphql.NewNonNull(graphql.String),
                },
            },
            Resolve: func(params graphql.ResolveParams) (interface{}, error) {
                user.Name = params.Args["userName"].(string)
                user.ID = params.Args["emailID"].(string)
                return user, nil
            },
        },
    },
})

schema, _ := graphql.NewSchema(graphql.SchemaConfig{
    Mutation: rootMutation,
})

http.HandleFunc("/graphql", func(w http.ResponseWriter, r *http.Request) {
    result := graphql.Do(graphql.Params{
        Schema:        schema,
        RequestString: r.URL.Query().Get("query"),
    })
    json.NewEncoder(w).Encode(result)
})

http.ListenAndServe(":8080", nil)
}

当我尝试从邮递员运行命令时，我收到错误消息 {"data":null,"errors":[{"message":"Schema is not configured for mutation","locations": [{"line":1,"column":1}]}]}

http://localhost:8080/graphql?query=mutation+_{createUser(userName:"ABC",emailID:"abc@abc.com"){userName,emailID}}

这是我试图从邮递员那里访问的 URL。我指的是 Getting Started With GraphQL Using Golang 在 Go 中实现变异

谁能帮忙看看这里需要做哪些改变？

【问题讨论】：

标签： go graphql schema graphql-go

【解决方案1】：

您用于突变的 shema 需要一个查询对象。

schema, _ := graphql.NewSchema(graphql.SchemaConfig{
    // QUERY NEEDED HERE !
    Mutation: rootMutation,
})

可以像这样定义对 userType 的查询并添加到架构中。

rootQuery := graphql.NewObject(graphql.ObjectConfig{
    Name: "Query",
    Fields: graphql.Fields{
        "lastUser" : &graphql.Field{ // "lastUser" name can be anything
            Type: userType,
        },
    },
})

schema, _ := graphql.NewSchema(graphql.SchemaConfig{
    Query:    rootQuery,
    Mutation: rootMutation,
})

这将修复 "Schema is not configured for mutations" 错误并拥有您的突变成功执行。

【讨论】：