json - 如何在 C# 中为 Amazon Dynamo DB 中的 Json 属性(列值)创建全局二级索引？

Question

我有一个包含列 Id 和 JSON 列的表。

Id       |       JSON
----------------------------------------------------------------
101      |  {"person_id":456,"f_name":"t", "l_name":"Jack"}
         |
102      |  {"person_id":123,"f_name":"M", "l_name":"Ron"}
         |
103      |  {"person_id":789,"f_name":"A", "l_name":"Tom"}

我能够在 Id 列上创建 GSI(全局二级索引)，但我想知道如何在 person_id 和 f_name 上创建 GSI。是否可以为 json 属性创建 GSI？根据观察，我能够在 Dynamo DB 表中的列上创建 GSI ..请提供 C#.Net 示例 ..

Answer 1

取自 http://aws.amazon.com/dynamodb/faqs/

Q: Is querying JSON data in DynamoDB any different?

No. You can create a Global Secondary Index or Local Secondary Index on any top-level JSON element. For example, suppose you stored a JSON document that contained the following information about a person: First Name, Last Name, Zip Code, and a list of all of their friends. First Name, Last Name and Zip code would be top-level JSON elements. You could create an index to let you query based on First Name, Last Name, or Zip Code. The list of friends is not a top-level element, therefore you cannot index the list of friends. For more information on Global Secondary Indexing and its query capabilities, see the Secondary Indexes section in this FAQ.

Q: If I have nested JSON data in DynamoDB, can I retrieve only a specific element of that data?

Yes. When using the GetItem, BatchGetItem, Query, or Scan APIs, you can define a ProjectionExpression to determine which attributes should be retrieved from the table. Those attributes can include scalars, sets, or elements of a JSON document.

虽然我还没有设法做到，或者看到任何通过云形成完成的例子。