amazon-web-services - 是否可以选择要在 DynamoDB 中返回的字段？

Question

我想知道是否有一种方法可以选择应包含在 dynamodb 查询或扫描结果中的字段。我尝试使用 AttributesToGet

def filter_ga_account_by_email(self, email):
    response = Table.scan(
        FilterExpression=Attr('client_email').eq(email),
        AttributesToGet=['id'],
    )

    return response['Items']

现在我有这个错误: ClientError: An error occurred (ValidationException) when calling the Scan operation: Can not use both expression and non-expression parameters in the same request: Non-expression parameters: {AttributesToGet} Expression parameters: {FilterExpression}


Answer 1

最简单的方法是添加projectionExpression 参数并指定要在字符串数组中返回的属性，一个工作示例:

    const getProducts = (user) => {
                    var params = {
                        TableName: process.env.PRODUCTS,
                        ScanIndexForward: false,
                        KeyConditionExpression: 'user = :hkey',
                        ExpressionAttributeValues: {
                            ':hkey': user,
                        },
                        Limit: 200,
                        ProjectionExpression: ['internal_type', 'requested_at']
                };
     return dynamoClient.query(params).promise();
}