UpdateExpression使用boto3为DynamoDB表中的更新函数获取动态值 [英] UpdateExpression taking dynamic values for update function in DynamoDB table using boto3

问题描述

这是第一部分的两部分问题 使用boto3实现的lambda更新DynamoDB表的值功能

This is two part question for first part Updating the value of DynamoDB table with boto3 implemented lambda function

现在我要实现的目标是要动态更新值

now what i am trying to achieve is having dynamic value to update

def lambda_handler(event, context):
    param = event['queryStringParameters']['employeID']
    name = event['queryStringParameters']['employeName']
    dynamodb = boto3.resource('dynamodb', region_name="us-east-1")
    table = dynamodb.Table('api_demo_employe')
    column = [cloumn1,cloumn2......]
    for i in range(0,len(column):

       query = 'SET {} = :f'.format(column[i])

       response = table.update_item(
           Key = {
               'employeID' : param
           },
           ExpressionAttributeValues = {
    
              ':f': name
          },
           UpdateExpression = query
    
          )

我遇到错误

 "errorMessage": "An error occurred (ValidationException) when calling the UpdateItem operation: One or more parameter values were invalid: Cannot update attribute employeID. This attribute is part of the key",

我知道问题出在我如何处理 UpdateExpression

I know the issue is with how i am handling UpdateExpression

有人可以帮我吗?

推荐答案

您正在尝试更新该项的密钥，该密钥无效.您将必须删除并重新创建该项目.

You’re trying to update the item’s key, which doesn’t work. You will have to delete and recreate the item.

有关详细信息，请参阅 Amazon DynamoDB文档:

For details, please refer to the Amazon DynamoDB documentation:

您不能使用UpdateItem更新任何主键属性.相反，您将需要删除该项目，然后使用PutItem创建具有新属性的新项目.

You cannot use UpdateItem to update any primary key attributes. Instead, you will need to delete the item, and then use PutItem to create a new item with new attributes.

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