无法使用Begins_with查询DynamoDB的项目列表 [英] Can't Query DynamoDB with Begins_with for list of Items

问题描述

我已经尝试查询DynamoDB数据了2天了.让我发疯.

I've been trying to query data from the DynamoDB for 2 days now. Driving me insane.

我在办公室有一张桌子.假设有两个办公室，科克和都柏林.我有一个名为"deskName"的列，其名称类似于"cork1"，"cork2"，"dub1"，"dub2".我希望能够在表中查询包含在同一表中的软木"或"dub"项，但我不想将整个表扫描回去.

I have a table for desks in an office. Say there is two offices, Cork and Dublin. I have a column called 'deskName' which would have names like 'cork1', 'cork2', 'dub1', 'dub2'. I want to be able to query the table for Items which contain 'cork' or 'dub' as they are in the same table but I don't want to SCAN the whole table back.

代码:

    const params = {
    TableName: process.env.DYNAMODB_DESKS_TABLE,
    //KeyConditionExpression: '#deskName = :deskName',
    KeyConditionExpression: "begins_with(#deskName, :deskName)",
    ExpressionAttributeNames: {
      "#deskName": "deskName"
    },
    ExpressionAttributeValues: {
      ":deskName": "cork"
    }
  }

  dynamodb.query(params, (error, result) => {
    if (error) {
      console.error(error);
      callback(null, {
        statusCode: error.statusCode || 501,
        headers: {'Content-Type': 'text/plain'},
        body: 'Couldn\'t get desks'
      });
      return;
    }

    const response = {
      statusCode: 200,
      body: JSON.stringify(result.Item)
    };

    callback(null, response);

  });

YAML:

HotDeskDesksDBTable:
  Type: 'AWS::DynamoDB::Table'
  DeletionPolicy: Retain
  Properties:
    AttributeDefinitions:
      -
        AttributeName: deskName
        AttributeType: S
    KeySchema:
      -
        AttributeName: deskName
        KeyType: HASH
    ProvisionedThroughput:
      ReadCapacityUnits: 1
      WriteCapacityUnits: 1
    TableName: ${self:provider.environment.DYNAMODB_DESKS_TABLE}

错误:

ValidationException: Query key condition not supported

当我的条件='cork-1'时，我设法退回了一件商品.我想获取所有以软木"开头的项目.

I managed to get one item coming back when I had the condition = 'cork-1'. I want to get every item that begins with 'cork'.

谢谢

推荐答案

您正在得到这个...

You're getting this...

Syntax error in module 'api/desks/get': SyntaxError
    KeyConditionExpression: "#deskName = :deskName",
    ^^^^^^^^^^^^^^^^^^^^^^
SyntaxError: Unexpected identifier

因为这个...

const params = {
  TableName: process.env.DYNAMODB_DESKS_TABLE,
  IndexName: 'deskName'
  KeyConditionExpression: "#deskName = :deskName",
  ExpressionAttributeNames:{
    "#deskName": "deskName"
  },
  ExpressionAttributeValues: {
    ":deskName": "cork"
  }
}

JavaScript对象的每个属性后都需要逗号.您在IndexName: 'deskName'之后缺少一个.

JavaScript objects require a comma after each property. You're missing one after IndexName: 'deskName'.

我建议使用 DocumentClient 因为它可以轻松地将Javascript数据类型映射到DynamoDB数据类型.

I would recommend the use of DocumentClient as it easily maps Javascript data types to DynamoDB data types.

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