问题描述

刚接触 DynamoDB，需要执行上述查询，但不确定如何操作.这是我目前正在尝试的，我收到以下错误.

New to DynamoDB and need to do the above query, but not sure how. Here is what I'm trying currently, and I'm getting the error below.

顺便说一句，我正在使用这个带有 DynamoDB 的 javascript 库:https://github.com/awslabs/dynamodb-document-js-sdk

Btw, I am using this javascript library w/ DynamoDB: https://github.com/awslabs/dynamodb-document-js-sdk

var ids = ['12313','12312313','12312313'];
var params = {
        TableName: 'apps',
        IndexName: 'state-app_id-index',
        KeyConditions: [
            DynamoDB.Condition("state", "EQ", "active"),
            DynamoDB.Condition("id", "IN", ids)
        ]
    };

    DynamoDB.query(params, function(error, response) {});

我得到的错误如下:

ValidationException:一个或多个参数值无效:ComparisonOperator IN 对 L AttributeValue 类型无效

ValidationException: One or more parameter values were invalid: ComparisonOperator IN is not valid for L AttributeValue type

推荐答案

KeyConditions 不支持 IN 运算符.KeyCondition 的文档说明了它支持哪些运算符:

KeyConditions does not support the IN operator. The documentation for KeyCondition says what operators it does support:

对于 KeyConditions，只有以下比较运算符是支持:

For KeyConditions, only the following comparison operators are supported:

EQ |LE |LT |通用电气 |GT |BEGINS_WITH |BETWEEN

EQ | LE | LT | GE | GT | BEGINS_WITH | BETWEEN

EQ 运算符也仅适用于单个值:

The EQ operator only works for a single value as well:

• EQ:相等.

AttributeValueList 只能包含一个 AttributeValue 类型的字符串、数字或二进制(不是集合类型).如果项目包含与请求中指定的类型不同类型的 AttributeValue 元素，则该值不匹配.例如，{"S":"6"} 不等于 {"N":"6"}.另外，{"N":"6"} 不等于 {"NS":["6", "2", "1"]}.p>

AttributeValueList can contain only one AttributeValue of type String, Number, or Binary (not a set type). If an item contains an AttributeValue element of a different type than the one specified in the request, the value does not match. For example, {"S":"6"} does not equal {"N":"6"}. Also, {"N":"6"} does not equal {"NS":["6", "2", "1"]}.

KeyConditionExpression，这是一种更新的、推荐的键过滤方法.这是文档中的一个片段(重点是我的):

The restrictions are basically the same for KeyConditionExpression, which is the newer, recommended way for filtering on keys. Here is a snippet from the documentation (emphasis mine):

条件必须对单个哈希键执行相等测试价值.条件还可以执行几个比较测试之一在单个范围键值上.Query 可以使用 KeyConditionExpression 来检索具有给定哈希和范围键值的一个项目，或几个哈希键值相同但范围键值不同的项目

The condition must perform an equality test on a single hash key value. The condition can also perform one of several comparison tests on a single range key value. Query can use KeyConditionExpression to retrieve one item with a given hash and range key value, or several items that have the same hash key value but different range key values

在您的情况下，您可以构建 FilterExpression 采用与 这个答案.

In your case, you could build out the FilterExpression in a similar way as described in this answer.

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