使用BatchWriteCommand写入编组数据时遇ValidationException问题求助

在AWS Lambda中使用BatchWriteCommand将编组（marshall）后的数据存入AWS DynamoDB时，触发ValidationException，错误信息为：The provided key element does not match the schema。

相关代码 #

export interface MyEvent {
    eventId: number
    eventTime: number
}

export interface MyModel {
    category: string
    status: string
    details: MyEvent[]
}

const dbClient = new DynamoDB({ apiVersion: "2012-08-10", "ap-southeast-2" })
export const ddbDocClient = DynamoDBDocument.from(dbClient)

export async function save(myItems: MyModel[]): Promise<void> {
    const marshalledData = myItems.map(event => ({
        PutRequest: {
            Item: marshall({
                myPK: "111111",
                mySortKey: event.category,
                status: event.status,
                eventDetails: event.details
            })
        }
    }))
    const command = new BatchWriteCommand({
        RequestItems: {
            ["events"]: marshalledData
        }
    })
    try {
        await ddbDocClient.send(command)
    } catch (e) {
        throw Error(`Error ${(<Error>e).message} `)
    }
}

尝试过的操作 #

若仅对eventDetails单独编组（eventDetails: marshall(event.details)），数据可存入但格式异常，会变成：

[ { "M" : { "M" : { "M" ....

而预期的正确格式应为：

{
    L: [
      {
        M: {

更新：编组后的数据结构 #

编组后数据的JSON结构如下：

{
    category: { S: 'Accounts' },
    status: { S: 'Active' },
    details: {
        L: [
            {
                M: {
                    eventId: { N: '101' },
                    eventTime: { N: '1686369780' }
                }
            },
            {
                M: {
                    eventId: { N: '102' },
                    eventTime: { N: '1686371880' }
                }
            }
        ]
    }
}

恳请帮忙排查问题原因。

内容的提问来源于stack exchange，提问作者Spartacus