Question

我在创建帖子时尝试自动添加时间戳。但它并不适用于appsync resolver-context-reference的例子。

https://docs.aws.amazon.com/appsync/latest/devguide/resolver-context-reference.html#time-helpers-in-util-time

{
    "version" : "2017-02-28",
    "operation" : "PutItem",
    "key": {
        "id" : $util.dynamodb.toDynamoDBJson($util.autoId())
    },

    #set( $myfoo = $util.dynamodb.toMapValues($ctx.args) )
    #set( $myFoo.version = $util.dynamodb.toNumber(1) )
    #set( $myFoo.timestamp = $util.time.nowISO8601() )

    "attributeValues" : $util.toJson($myFoo)
}

Answer 1

这是您要查看的内容的一个有效示例（取自我的AppSync API解析程序）。注意＆＃34; messageId＆＃34;和＆＃34; createdDate＆＃34;属性。这就是如何在写入DDB时添加日期。

$$ se(P_i) = P_i \sqrt{\sum^i_{j=1} ( \frac{q_j}{r_j p_j})} $$

Answer 2

将解析器更改为以下

{
    "version" : "2017-02-28",
    "operation" : "PutItem",
    "key": {
        "id" : $util.dynamodb.toDynamoDBJson($util.autoId())
    },

    #set( $myfoo = $util.dynamodb.toMapValues($ctx.args) )
    #set( $myFoo.version = $util.dynamodb.toNumber(1) )
    #set( $myFoo.timestamp = $util.dynamodb.toDynamoDB($util.time.nowISO8601()) )

    "attributeValues" : $util.toJson($myFoo)
}

请注意更改将$util.time.nowISO8601()与$util.dynamodb.toDynamoDB()

的呼叫包裹起来

Answer 3

对于dynamoDB，String应通过$util更改为dynamodb类型。因此，将时间字符串更改为dynamoDB类型后，它将起作用。

#set( $myFoo.timestamp = $util.time.nowISO8601() )
=>  
#set( $myFoo.timestamp = $util.dynamodb.toDynamoDB($util.time.nowISO8601())

使用Dynamodb通过AWS Appsync解析程序自动添加时间戳

3 个答案: