使用 Ruby SDK 的 DynamoDB 查询

Question

我真的很难使查询正常工作。我正在尝试获取主键 ('keyword') 等于 'compost spoons'.

的所有项目

这是我的一件物品：

{
  "keyword": "compost spoons",
  "created_at": "2020-08-12T11:31:21+00:00"
}

这是我查询中的参数：

params = {
    table_name: "servings", 
    select: "ALL_ATTRIBUTES", 
    return_consumed_capacity: "INDEXES",
    key_condition_expression: "keyword = :keyword_val",
    expression_attribute_values: {
        "keyword_val" => "compost spoon"
    }
  }

它通过的错误：

"ExpressionAttributeValues contains invalid key: Syntax error; key: \"keyword_val\""

要使查询正常工作，参数应该是什么？

架构：

{
  "AttributeDefinitions": [
    {
      "AttributeName": "keyword",
      "AttributeType": "S"
    },
    {
      "AttributeName": "created_at",
      "AttributeType": "S"
    }
  ],
  "TableName": "servings",
  "KeySchema": [
    {
      "AttributeName": "keyword",
      "KeyType": "HASH"
    },
    {
      "AttributeName": "created_at",
      "KeyType": "RANGE"
    }
  ],
  "TableStatus": "ACTIVE",
  "CreationDateTime": "2020-08-14T10:26:55.528Z",
  "ProvisionedThroughput": {
    "LastIncreaseDateTime": "1970-01-01T00:00:00.000Z",
    "LastDecreaseDateTime": "1970-01-01T00:00:00.000Z",
    "NumberOfDecreasesToday": 0,
    "ReadCapacityUnits": 5,
    "WriteCapacityUnits": 5
  },
  "TableSizeBytes": 168,
  "ItemCount": 3,
  "TableArn": "arn:aws:dynamodb:ddblocal:000000000000:table/servings"
}

Answer 1

您在 expression_attribute_values 中的 keyword_val 前面似乎少了一个冒号。我认为应该是：

params = {
    table_name: "servings", 
    select: "ALL_ATTRIBUTES", 
    return_consumed_capacity: "INDEXES",
    key_condition_expression: "keyword = :keyword_val",
    expression_attribute_values: {
        ":keyword_val" => "compost spoon".  // <---- CHANGE IS HERE!!
    }
  }

使用 Ruby SDK 的 DynamoDB 查询

DynamoDB query with Ruby SDK

ruby

amazon-dynamodb

dynamodb-queries