Question

我试图为现有的Lambda函数配置DAX，该函数可将数据读取和写入DynamoDB。在引入DAX之前，一切正常，然后，写入停止工作，正在写入的数据保持不变。

在调试时，我发现它们因以下异常而失败：

Write operation failed without negative acknowledgement 
Cannot convert undefined or null to object
at Function.keys (<anonymous>)
at Function._encodeAttributeValueInternal (/var/task/node_modules/amazon-dax-client/src/AttributeValueEncoder.js:173:23)
at Function.encodeAttributes (/var/task/node_modules/amazon-dax-client/src/AttributeValueEncoder.js:144:29)
at Function.encodeValuesWithNames (/var/task/node_modules/amazon-dax-client/src/Encoders.js:227:55)
at Encoders.encodeValues (/var/task/node_modules/amazon-dax-client/src/Encoders.js:67:23)
at Promise.resolve.then (/var/task/node_modules/amazon-dax-client/generated-src/Stubs.js:163:24)
at propagateAslWrapper (/var/task/node_modules/async-listener/index.js:504:23)
at /var/task/node_modules/async-listener/glue.js:188:31
at /var/task/node_modules/async-listener/index.js:541:70
at /var/task/node_modules/async-listener/glue.js:188:31

Answer 1

正在写入的数据具有一些“可选”字段。所写的项目就像：

{
    requiredField1: "Some value",
    requiredField2: true,
    optionalField1: "abc",
    optionalField2: null,
    optionalField3: undefined,
}

DynamoDB的一切都很好，很花哨，没有抱怨，但是显然DAX对undefined并不宽容。将其更改为null使我克服了错误。

DAX放置项失败，显示“无法将未定义或null转换为对象”

1 个答案: