Azure Cosmos Posting a File to use in a Logic App

Question

Hello I am trying to pull data from my cosmos database and then modify it and then send it out to a user through an email which has an attachment of a tab delimited text document of the data.

So far I have the logic app set up to recieve the data and the query to get the data and the method to change the data into the format I want. I need to figure out a way to create a tab delimited file and send that to my logic app. I am only able to get a string to get sent to my logic app of all the data. Here is the code I am working with:

string query = $"Select * from c";
        var restrictions = await _cosmosService.QueryItemsAsync<Data>(Database, query);

        if (restrictions == null)
            return new NoContentResult();
        string tabDelimitedText = ConvertToTabDelimited(restrictions);

        byte[] tabDelimitedBytes = System.Text.Encoding.UTF8.GetBytes(tabDelimitedText);

        MemoryStream stream = new MemoryStream(tabDelimitedBytes);
        var rtn = new FileStreamResult(stream, "text/plain");

        await _client.PostAsync(EmailTriggerUrl, new StringContent(rtn, Encoding.UTF8, "application/text"));
        return rtn;

private string GetTabDelimitedText(List<Person> people)
    {
        StringWriter textWriter = new StringWriter();
        textWriter.WriteLine("Name\tAge\tCity");
        foreach (var person in people)
        {
            textWriter.WriteLine($"{person.Name}\t{person.Age}\t{person.City}");
        }
        return textWriter.ToString();
    }

I know that I need to change the PostAsync from a StringContent but I am unsure what is needs to be

Answer 1

I am trying to pull data from my cosmos database and then modify it and then send it out to a user through an email.

• I extracted data from Cosmos Db using cosmosClient and stored it as a Delimited-Text file in the Blob container using the below code. Then I used Logic Apps to send a mail.

Below are the steps I followed:

• cosmosDbEP and cosmosDbKey are created an instance called cosmosClient which is used to interact with the Cosmos DB. query is used to retrieve data from the db.

• blobServClient is created using blobConnStr which is used to interact with the Azure Blob Storage account.

• GetTabDelimitedText method takes a Data as parameter. It uses string interpolation to create a string where data is seperated by tabs \t.

• blobName is used to generate a unique blob name for each and every item in cosmos db and tab-delimited data is uploaded to Blob storage as a text file.

Below is the code I tried with:

CosmosClient cosmosClient = new CosmosClient(cosmosDbEP, cosmosDbKey);
var cont = cosmosClient.GetContainer(dbId, contId);
var query = new QueryDefinition("SELECT * FROM c");
var queryIterator = cont.GetItemQueryIterator<Data>(query);

BlobServiceClient blobServClient = new BlobServiceClient(blobConnStr);
BlobContainerClient contClient = blobServClient.GetBlobContainerClient(blobContName);

while (queryIterator.HasMoreResults)
{
    var response = await queryIterator.ReadNextAsync();

    foreach (var item in response)
    {
        string tabDelimitedContent = GetTabDelimitedText(item); 

        string blobName = Guid.NewGuid().ToString() + ".txt";

        BlobClient blobClient = contClient.GetBlobClient(blobName);

        using (Stream stream = new MemoryStream(Encoding.UTF8.GetBytes(tabDelimitedContent)))
        {
            await blobClient.UploadAsync(stream, new BlobUploadOptions { HttpHeaders = new BlobHttpHeaders { ContentType = "text/plain" } });
        }
        Console.WriteLine($"Uploaded item to Blob Storage: {blobName}");
    }
}
Console.WriteLine("Data transfer completed.");

Output:

Uploaded item to Blob Storage: 8ee63e0d-cc6d-47b6-ad69-af40097c9134.json
Uploaded item to Blob Storage: 5f24d20c-baff-4f43-a226-e784d333ac72.json
Uploaded item to Blob Storage: 52f0fc8c-6ab8-412b-a700-d36f7ba3aae8.json
Uploaded item to Blob Storage: ca9f2958-0a2c-4eae-9734-605490ccad3d.json
Uploaded item to Blob Storage: e97888ca-3ef2-4c8e-994c-369cd01ad24b.json
Data transfer completed.

Data stored in Blob:

1   Balaji  23  Male
2   Pavan   20  Male
3   Likitha 24  Female
4   Sai 24  Female
5   Venkatesh   25  Male

Design in Logic Apps:

• In Logic Apps the data which is stored in Blob container is added by mentioning container name /tbalaji. Now, the data can be sent to mail in Logic Apps as you can see below.