向 DynamoDB 发送查询命令时出错：TypeError：无法读取未定义的属性（读取“0”）

Question

我有一个名为AllowListedItems 的DynamoDB 表。它具有 ID、名称和ignoreNoTraffic 字段。它在“name”字段上有一个名为 name-index 的 GSI。我正在尝试查询带有名称的ignoreNoTraffic 值。下面是我的 Typescript 代码。我使用 AWS SDK V3 进行以下导入：

import { DynamoDB, GetItemCommand, ScanCommand, QueryCommand } from "@aws-sdk/client-dynamodb";
import { unmarshall } from "@aws-sdk/util-dynamodb";

private async getIgnoreNoTraffic(): Promise<boolean> {
    const params = {
        TableName: Tables.ALLOW_LISTED_ITEMS,
        IndexName: "name-index",
        KeyConditionExpression: "#nameAttr = :nameValue",
        ExpressionAttributeNames: {
            "#nameAttr": "name" 
        },
        ExpressionAttributeValues: {
            ":nameValue": this.name,
        },
    };

    try {
        const items = await dynamodbUtils.queryValuesFromDB(params);

        if (items.length > 0) {
            const item = items[0];
            console.log("Received item:", item);

            if (item. ignoreNoTraffic !== undefined) {
                return item. ignoreNoTraffic.BOOL || false;  
            } else {
                return false;
            }
        } else {
            console.log("Item could not be fetched from the table using name");
            return false;
        }
    } catch (error) {
        console.error("Error fetching ignoreNoTraffic by name:", error);
        throw error;
    }
}

以下是dynamoDB功能：

export async function queryValuesFromDB(params: any) {
console.log("Querying DynamoDB with params2:", JSON.stringify(params, null, 2));

try {
    const data = await client.send(new QueryCommand(params));

    if (!data) {
        console.error("DynamoDB returned undefined or null data.");
        throw new Error("DynamoDB returned undefined or null data.");
    }

    console.log("Received raw data from DynamoDB:", JSON.stringify(data, null, 2));

    if (!data.Items) {
        console.log("Items field is missing from the data.");
        throw new Error("DynamoDB response does not contain 'Items'.");
    }

    if (data.Items.length > 0) {
        console.log("Successfully retrieved items:", data.Items);
        return data.Items; // Directly return the items as JSON
    } else {
        console.log("No items found for the query.");
        return [];
    }
} catch (error) {
    console.error("Error executing DynamoDB query:", error);

    if (error instanceof Error) {
        console.error("Error message:", error.message);
        throw new Error(`DynamoDB Query Error: ${error.message}`);
    } else {
        console.error("Unknown error occurred:", JSON.stringify(error));
        throw new Error("An unknown error occurred during DynamoDB query.");
    }
}

}

当我运行上面的代码时，出现以下错误：

ERROR   Error while sending query command to DynamoDB: TypeError: Cannot read properties of undefined (reading '0')

我有以下信息日志：

INFO    Querying DynamoDB with params3: 
{
"TableName": "AllowListedItems",
"IndexName": "name-index",
"KeyConditionExpression": "#nameAttr = :nameValue",
"ExpressionAttributeNames": {
    "#nameAttr": "name"
},
"ExpressionAttributeValues": {
    ":nameValue": "development"
}
}

为什么我会收到此错误？感谢任何建议/帮助。

我尝试在 AWS 控制台上使用 AWS SDK V2 通过 javascript lambda 运行上述 params 命令。但这确实有效！

    const AWS = require('aws-sdk');
const dynamodb = new AWS.DynamoDB();
const docClient = new AWS.DynamoDB.DocumentClient();

async function queryValuesFromDB(params) {
    console.log("Querying DynamoDB with params:", JSON.stringify(params, null, 2));

    try {
        const data = await docClient.query(params).promise();
        console.log("Received raw data from DynamoDB:", JSON.stringify(data, null, 2));

        if (data && data.Items && data.Items.length > 0) {
            console.log("Successfully retrieved items:", data.Items);
            return data.Items; 
        } else {
            console.log("No items found for the query.");
            return [];
        }
    } catch (error) {
        console.error("Error executing DynamoDB query:", error.message || error);
        throw new Error(`DynamoDB Query Error: ${error.message || error}`);
    }
}

async function getIgnoreNoTraffic(name) {
    const params = {
        TableName: 'AllowListedItems', 
        IndexName: 'name-index', 
        KeyConditionExpression: "#nameAttr = :nameValue",
        ExpressionAttributeNames: {
            "#nameAttr": "name" 
        },
        ExpressionAttributeValues: {
            ":nameValue": name, 
        },
    };

    try {
        const items = await queryValuesFromDB(params);
        if (items.length > 0) {
            const item = items[0];
            if (item. ignoreNoTraffic !== undefined) {
                return item. ignoreNoTraffic;
            } else {
                return false;
            }
        } else {
            console.log("Item could not be fetched from the table using name");
            return false;
        }
    } catch (error) {
        console.error("Error fetching ignoreNoTraffic by name:", error);
        throw error;
    }
    }

    exports.handler = async (event) => {
        const name = event.name || "test-name"; 
        try {
            const ignoreNoTraffic = await getIgnoreNoTraffic(name);
            console.log("Ignore result:", ignoreNoTraffic);
            return {
                statusCode: 200,
                body: JSON.stringify({
                    message: "Success",
                    ignoreNoTraffic: ignoreNoTraffic
                }),
            };
        } catch (error) {
            return {
                statusCode: 500,
                body: JSON.stringify({
                    message: "Error",
                    error: error.message,
                }),
            };
        }
    };

Answer 1

在 V3 中，您不使用 docClient，但继续使用本机 JSON。

阅读这篇博客文章，它可以帮助您为客户端配置正确的参数：

https://aws.amazon.com/blogs/database/exploring-amazon-dynamodb-sdk-clients/