CosmosDB 在读取时从外部 API 返回数据

Question

I am attempting to write an Azure CosmosDB integration (Core SQL Api) that integrates with an external service to provide some of the query data. As an example, I need a query made on Cosmos DB to convert some of the data returned (eg ID's) by the query into real data by calling an external service via a REST API. This should only happen when querying certain columns.

I initially investigated using a JS stored procedure and/or a UDF to make this external call, but the JS environment seems to be extremely limited and doesn't provide any way to make external calls. I then tried using this https://github.com/Oblarg/cosmosdb-storedprocs-ts repository, which uses webpack to bundle all of node.js into the stored procedure, allowing node modules to be used in stored procedures. Whilst this does allow some node modules to be used, whenever I try and use "https", "fetch", or "axios" modules to make an HTTP GET request I get errors (the same code works fine in a normal node environment, but I'm not a JS expert and can't seem to work past these errors). After a day of attempts it seems like the stored procedure approach is not possible.

Is this the case or is there some way of making HTTP GET requests from a JS stored procedure? If not possible with stored procedures, are there any other techniques to achieve the requirement of reading data from a remote API when querying cosmos DB?

Thanks

Answer 1

There is no way to achieve this from CosmosDB directly, for queries you also cannot use the change feed as the document dont change, so really your only option is to use a function or some preprocessor app to handle it, as you say its not ideal but there is no other solution here. If it was an insert or an update then change feed would allow you to do this but for plain queries its not possible.