基于Dynamose Schema在NoSQL Workbench获取DynamoDB数据模型的问题

问题概述 #

使用Dynamoose库自动生成对应Schema的DynamoDB表时，遇到以下问题：

• 无法在NoSQL Workbench可视化工具中找到该表，也无法导出指定格式的DynamoDB数据模型
• 执行aws dynamodb describe-table命令返回的表元数据中，缺失Schema里定义的content属性

用到的Schema代码 #

import { Schema } from 'dynamoose';

export const NotificationSchema = new Schema({
  "id": {
    "type": "String",
    "hashKey": true,
  },
  "targetId": {
    "type": "String",
    "index": {
      "type": "global",
      "rangeKey": "status",
    },
  },
  "userId": {
    "type": "String",
    "index": {
      "type": "global",
      "rangeKey": "status",
    },
  },
  "content": {
    "type": "String",
  },
  "status": {
    "type": "String",
  },
  "createAt": {
    "type": "String",
  },
});

执行的命令 #

aws dynamodb describe-table --table-name aws-nestjs-starter-dev-notification-table --endpoint-url http://localhost:8000

返回的缺失content的元数据 #

{
  "AttributeDefinitions": [
    {
      "AttributeName": "id",
      "AttributeType": "S"
    },
    {
      "AttributeName": "targetId",
      "AttributeType": "S"
    },
    {
      "AttributeName": "userId",
      "AttributeType": "S"
    },
    {
      "AttributeName": "status",
      "AttributeType": "S"
    }
  ],
  "TableName": "aws-nestjs-starter-dev-notification-table",
  "KeySchema": [
    {
      "AttributeName": "id",
      "KeyType": "HASH"
    }
  ],
  "TableStatus": "ACTIVE",
  "CreationDateTime": {},
  "ProvisionedThroughput": {
    "LastIncreaseDateTime": {},
    "LastDecreaseDateTime": {},
    "NumberOfDecreasesToday": 0,
    "ReadCapacityUnits": 1,
    "WriteCapacityUnits": 1
  },
  "TableSizeBytes": 381,
  "ItemCount": 4,
  "TableArn": "arn:aws:dynamodb:ddblocal:000000000000:table/aws-nestjs-starter-dev-notification-table",
  "GlobalSecondaryIndexes": [
    {
      "IndexName": "targetIdGlobalIndex",
      "KeySchema": [
        {
          "AttributeName": "targetId",
          "KeyType": "HASH"
        },
        {
          "AttributeName": "status",
          "KeyType": "RANGE"
        }
      ],
      "Projection": {
        "ProjectionType": "ALL"
      },
      "IndexStatus": "ACTIVE",
      "ProvisionedThroughput": {
        "ReadCapacityUnits": 1,
        "WriteCapacityUnits": 1
      },
      "IndexSizeBytes": 378,
      "ItemCount": 3,
      "IndexArn": "arn:aws:dynamodb:ddblocal:000000000000:table/aws-nestjs-starter-dev-notification-table/index/targetIdGlobalIndex"
    },
    {
      "IndexName": "userIdGlobalIndex",
      "KeySchema": [
        {
          "AttributeName": "userId",
          "KeyType": "HASH"
        },
        {
          "AttributeName": "status",
          "KeyType": "RANGE"
        }
      ],
      "Projection": {
        "ProjectionType": "ALL"
      },
      "IndexStatus": "ACTIVE",
      "ProvisionedThroughput": {
        "ReadCapacityUnits": 1,
        "WriteCapacityUnits": 1
      },
      "IndexSizeBytes": 378,
      "ItemCount": 3,
      "IndexArn": "arn:aws:dynamodb:ddblocal:000000000000:table/aws-nestjs-starter-dev-notification-table/index/userIdGlobalIndex"
    }
  ]
}

属性缺失的原因 #

DynamoDB是无Schema数据库，describe-table返回的AttributeDefinitions仅包含表键（主键/排序键）和索引键的属性信息。content属于普通非键属性，不会被包含在这个结果里，这是DynamoDB的正常行为，并非Dynamoose的问题。

解决属性显示与Workbench识别问题 #

1. 让NoSQL Workbench识别所有属性 #

NoSQL Workbench通过扫描表中现有数据来推断完整的属性列表，所以需要：

• 向表中插入至少一条包含content、createAt等非键属性的记录
• 在NoSQL Workbench中刷新表的元数据，或重新导入该表
• 此时Workbench就能识别到所有定义的属性，也能正常在可视化工具中显示该表

2. 获取指定格式的数据模型 #

通过NoSQL Workbench导出

1. 确保表中有包含所有属性的样本数据，让Workbench识别完整结构
2. 打开NoSQL Workbench，进入「Data Modeler」模块
3. 将目标表导入到数据模型中，补充模型元数据（如作者、版本、描述等）
4. 导出时选择对应的JSON格式，即可得到类似示例的模型文件

通过代码手动生成

如果需要自动化生成，可以基于Dynamoose Schema和DynamoDB表元数据拼接：

• 从Dynamoose Schema中提取所有属性（键属性+非键属性）的名称和类型
• 调用describe-table获取表的结构、索引、吞吐量等信息
• 按照目标格式的结构组合这些数据，添加自定义元数据和样本数据即可

内容的提问来源于stack exchange，提问作者Tabares