【发布时间】:2019-05-23 19:38:37
【问题描述】:
我已经使用 graphql-go 库在 go 中成功设置了 GraphQL 服务器。但是,在进行查询时传递查询参数时,我似乎遇到了错误。所以我有一个名为emails 的查询,它以address 作为参数并查询数据库以返回与给定address 关联的所有电子邮件的结果。当我直接传递address 参数时,一切似乎都运行良好,您可以从这张图片中看到:
但是,当我向它传递查询参数时,它似乎不起作用,如下所示:
我不认为这两个语句应该给出相同的结果。然而,情况似乎并非如此。有人可以帮我理解为什么我会收到这些错误吗?这是我的代码
package main
import (
"log"
"net/http"
"github.com/graphql-go/graphql"
"github.com/graphql-go/handler"
"github.com/aws/aws-sdk-go/aws"
"github.com/aws/aws-sdk-go/aws/credentials"
"github.com/aws/aws-sdk-go/aws/session"
"github.com/aws/aws-sdk-go/service/dynamodb"
"github.com/aws/aws-sdk-go/service/dynamodb/dynamodbattribute"
)
var sess, _ = session.NewSession()
// Email - Used to represent a single email object stored in
// dynamodb. Fields 'attachments', 'body-html', 'stripped-html' and
// 'stripped-text' may be empty.
type Email struct {
To string `json:"to"`
Recipients []string `json:"recipients"`
Token string `json:"token"`
Sender string `json:"sender"`
Subject string `json:"subject"`
Timestamp string `json:"timestamp"`
Attachments []string `json:"attachments"`
Mime string `json:"mime"`
BodyPlain string `json:"body_plain"`
BodyHTML string `json:"body_html"`
StrippedText string `json:"stripped_text"`
StrippedHTML string `json:"stripped_html"`
}
// emailType - a new graphql object representing a single email
var emailType = graphql.NewObject(graphql.ObjectConfig{
Name: "Email",
Fields: graphql.Fields{
"to": &graphql.Field{
Type: graphql.String,
},
"recipients": &graphql.Field{
Type: graphql.NewList(graphql.String),
},
"token": &graphql.Field{
Type: graphql.String,
},
"sender": &graphql.Field{
Type: graphql.String,
},
"subject": &graphql.Field{
Type: graphql.String,
},
"attachments": &graphql.Field{
Type: graphql.NewList(graphql.String),
},
"timestamp": &graphql.Field{
Type: graphql.String,
},
"mime": &graphql.Field{
Type: graphql.String,
},
"body_plain": &graphql.Field{
Type: graphql.String,
},
"body_html": &graphql.Field{
Type: graphql.String,
},
"stripped_text": &graphql.Field{
Type: graphql.String,
},
"stripped_html": &graphql.Field{
Type: graphql.String,
},
},
})
// emailType - a new graphql object representing a deleted email.
var deleteEmailType = graphql.NewObject(graphql.ObjectConfig{
Name: "Email",
Fields: graphql.Fields{
"to": &graphql.Field{
Type: graphql.String,
},
"token": &graphql.Field{
Type: graphql.String,
},
},
})
func disableCors(h http.Handler) http.Handler {
return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
w.Header().Set("Access-Control-Allow-Origin", "*")
w.Header().Set("Access-Control-Allow-Methods", "POST, GET, OPTIONS, PUT, DELETE")
w.Header().Set("Access-Control-Allow-Headers", "Accept, Authorization, Content-Type, Content-Length, Accept-Encoding")
// I added this for another handler of mine,
// but I do not think this is necessary for GraphQL's handler
if r.Method == "OPTIONS" {
w.Header().Set("Access-Control-Max-Age", "86400")
w.WriteHeader(http.StatusOK)
return
}
h.ServeHTTP(w, r)
})
}
func main() {
// configures the rootQuery for the graphQL API
rootQuery := graphql.NewObject(graphql.ObjectConfig{
Name: "Query",
Fields: graphql.Fields{
"emails": &graphql.Field{
Type: graphql.NewList(emailType),
Args: graphql.FieldConfigArgument{
"address": &graphql.ArgumentConfig{
Type: graphql.String,
},
},
Resolve: func(params graphql.ResolveParams) (interface{}, error) {
address := params.Args["address"].(string)
svc := dynamodb.New(sess)
result, err := svc.Query(&dynamodb.QueryInput{
TableName: aws.String("emails_db"),
KeyConditions: map[string]*dynamodb.Condition{
"to": {
ComparisonOperator: aws.String("EQ"),
AttributeValueList: []*dynamodb.AttributeValue{
{
S: aws.String(address),
},
},
},
},
})
if err != nil {
return nil, nil
}
// unmarshalls all the emails to recs
recs := []Email{}
err = dynamodbattribute.UnmarshalListOfMaps(result.Items, &recs)
if err != nil {
return nil, nil
}
return recs, nil
},
},
},
})
// configures the rootMutation for the graphQL API
rootMutation := graphql.NewObject(graphql.ObjectConfig{
Name: "Mutation",
Fields: graphql.Fields{
"email": &graphql.Field{
Type: deleteEmailType,
Args: graphql.FieldConfigArgument{
"address": &graphql.ArgumentConfig{
Type: graphql.NewNonNull(graphql.String),
},
"token": &graphql.ArgumentConfig{
Type: graphql.NewNonNull(graphql.String),
},
},
Resolve: func(params graphql.ResolveParams) (interface{}, error) {
address := params.Args["address"].(string)
token := params.Args["token"].(string)
svc := dynamodb.New(sess)
_, err := svc.DeleteItem(&dynamodb.DeleteItemInput{
TableName: aws.String("emails_db"),
Key: map[string]*dynamodb.AttributeValue{
"to": {
S: aws.String(address),
},
"token": {
S: aws.String(token),
},
},
})
if err != nil {
return nil, err
}
// unmarshalls all the emails to recs
rec := Email{To: address, Token: token}
return rec, nil
},
},
},
})
// configures routes
schema, _ := graphql.NewSchema(graphql.SchemaConfig{
Mutation: rootMutation,
Query: rootQuery,
})
h := handler.New(&handler.Config{
Schema: &schema,
Pretty: true,
GraphiQL: true,
})
http.Handle("/graphql", disableCors(h))
log.Fatal(http.ListenAndServe(":80", nil))
}
【问题讨论】:
-
Unknown type \"String\"听起来像一个错误;还比较非常相似的github.com/graphql-go/graphql/issues/331,并浏览问题似乎有一个更广泛的问题,即库在这个特定点不相信内置标量。