我正尝试编写一个非常简单的Go函数来向DynamoDB表中插入条目。
我正在学习AWS文档站点上提供的教程，但是由于某种原因，函数 * dynamodbattribut.MarshalMap * 返回了一个空Map。
代码编译并运行，但在试图插入记录时中断，因为它在map中找不到所需的键。一个小println操作显示map是空的，即使创建它的结构体不是空的。
任何帮助都是感激的!

package main

import (
    "context"
    "fmt"

    "github.com/aws/aws-sdk-go/aws"

    "github.com/aws/aws-lambda-go/lambda"
    "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"
)

// Item Struct for Fruit Item
type Item struct {
    fruitID   int
    fruitName string
}

/*HandleRequest handles the lambda request.*/
func HandleRequest(ctx context.Context) (string, error) {
    // Initialize a session that the SDK will use to load
    // credentials from the shared credentials file ~/.aws/credentials
    // and region from the shared configuration file ~/.aws/config.
    sess := session.Must(session.NewSessionWithOptions(session.Options{
        SharedConfigState: session.SharedConfigEnable,
    }))

    // Create DynamoDB client
    svc := dynamodb.New(sess)

    item := Item{
        fruitID:   2,
        fruitName: "Orange",
    }

    fmt.Println(item)

    av, err := dynamodbattribute.MarshalMap(item)
    if err != nil {
        fmt.Println("Got error marshalling new fruit item: ")
        fmt.Println(err.Error())
        return "", err
    }

    fmt.Println("av: ", av)
    fmt.Println("ln: ", len(av))
    fmt.Println("KEY VALUE PAIRS::")
    for key, value := range av {
        fmt.Println("Key:", key, "Value:", value)
    }

    tableName := "fruits"

    input := &dynamodb.PutItemInput{
        Item:      av,
        TableName: aws.String(tableName),
    }

    _, err = svc.PutItem(input)
    if err != nil {
        fmt.Println("Got error inserting new fruit item: ")
        fmt.Println(err.Error())
        return "", err
    }

    return "SUCCESS!", nil
}

func main() {
    lambda.Start(HandleRequest)
}

• Lambda的日志输出 *

START RequestId: 82f120d9-6bba-40d9-9204-136d491dbb88 Version: $LATEST
{2 Orange}
av:  map[]
ln:  0
KEY VALUE PAIRS::
Got error inserting new fruit item: 
ValidationException: One or more parameter values were invalid: Missing the key fruitId in the item
    status code: 400, request id: QUJG8R8EHPO65O1JFVI98PRQ1VVV4KQNSO5AEMVJF66Q9ASUAAJG
ValidationException: One or more parameter values were invalid: Missing the key fruitId in the item
    status code: 400, request id: QUJG8R8EHPO65O1JFVI98PRQ1VVV4KQNSO5AEMVJF66Q9ASUAAJG: requestError
null
END RequestId: 82f120d9-6bba-40d9-9204-136d491dbb88