Dynamics Community Forum Thread Details

How to use Dataverse Web API to upload file as JSON

Hi,

I try to upload a adaptive card to dataverse by using a column declared as a file.

Even I need some meta information about team and channel for Microsoft Teams. By writing the information inside the table will trigger a work flow inside the professional environment.

I'm using Java:

public record AdaptiveCards (String craa5_team, String craa5_channel, String craa5_adaptivecards) {
}

File file = ResourceUtils.getFile("classpath:payloads/webhook_payload_02.json");

String base64;
try (FileInputStream fis = new FileInputStream(file); ByteArrayOutputStream baos = new ByteArrayOutputStream()) {
    byte[] buffer = new byte[1024];
    int len;
    while ((len = fis.read(buffer)) != -1) {
        baos.write(buffer, 0, len);
    }
    base64 = Base64.getEncoder().encodeToString(baos.toByteArray());
}

AdaptiveCards payload = new AdaptiveCards("team", "channel", base64);
RequestBody requestBody = RequestBody.create( new ObjectMapper().writeValueAsString(payload), MediaType.parse("application/json") );
Request request = new Request.Builder()
.url( https://abc.crm4.dynamics.com/api/data/v9.2/tablename")
.post(requestBody)
.addHeader("Authorization", "Bearer " + accessToken) 
.addHeader("Accept", "application/json") .build(); 

try (Response response = new OkHttpClient().newCall(request).execute()) {

By sending out the request I running in the error message:

Connection returned HTTP code: 400 with message: {"error":{"code":"0x80060888","message":"The file attribute value sent ... is not a valid Guid."

Using a UUID returns success but I wonder how should I upload the file.

https://learn.microsoft.com/en-us/power-apps/developer/data-platform/file-column-data?tabs=webapi

Does anybody has expierence and could give me an advice?

Thanks,

Markus

Categories:

Dynamics 365 general

To upload a file (like your Adaptive Card JSON) to a Dataverse file column, you're hitting an error because Dataverse expects a two-step process or multipart/form-data, not a Base64 string directly within the entity's JSON payload for a file column.

Create/Update the entity record without the file content.
Then, send a separate PUT request to the specific file column endpoint (/api/data/v9.2/entity_collection(record_id)/file_column_name) with the binary content of your file (or Base64 wrapped in {"value":"..."} JSON).
The error "not a valid Guid" means Dataverse is misinterpreting your Base64 string as an attempt to provide a file reference GUID, not the file content.