How do you check that a container exists in Azure Blob Storage V12

Question

Previously when using Azure Blob Storage SDK V11, if you wanted to Create a container but were unsure if the container existed you could use CreateIfNotExists.

However in version V12, CreateIfNotExists is no longer available and the only example I can find from Microsoft is to simply create a Container without checking if it already exists.

So, does anyone know the best practice in V12 to check if a container exists before trying to create it.

Incidentally, I'm developing for ASP.Net Core 3.1.

Answer 1

In v12, there are 2 ways to check if the container exists or not.

1.

BlobServiceClient blobServiceClient = new BlobServiceClient(connectionString);

//get a BlobContainerClient
var container = blobServiceClient.GetBlobContainerClient("the container name");
            
//you can check if the container exists or not, then determine to create it or not
bool isExist = container.Exists();
if (!isExist)
{
    container.Create();
}

//or you can directly use this method to create a container if it does not exist.
 container.CreateIfNotExists();

You can directly create a BlobContainerClient, then use code below:

//create a BlobContainerClient 
BlobContainerClient blobContainer = new BlobContainerClient("storage connection string", "the container name");
    
//use code below to check if the container exists, then determine to create it or not
bool isExists = blobContainer.Exists();
if (!isExist)
{
   blobContainer .Create();
}
    
//or use this code to create the container directly, if it does not exist.
blobContainer.CreateIfNotExists();

Answer 2

The accepted answer is fine. But I usually use the async version of it.

var _blobServiceClient = new BlobServiceClient(YOURCONNECTIONSTRING);
var containerClient = _blobServiceClient.GetBlobContainerClient(YOURCONTAINERNAME);
await containerClient.CreateIfNotExistsAsync(Azure.Storage.Blobs.Models.PublicAccessType.BlobContainer);

The version I'm using is Azure.Storage.Blobs v12.4.1

Answer 3

However in version V12, CreateIfNotExists is no longer available and the only example I can find from Microsoft is to simply create a Container without checking if it already exists.

I am not sure why do you say CreateIfNotExists is no longer available in version 12 of storage client library. It is certainly there in BlobContainerClient class. Here's the direct link: CreateIfNotExists.

    var connectionString = "UseDevelopmentStorage=true";            
    var containerClient = new BlobContainerClient(connectionString, containerName);
    containerClient.CreateIfNotExists();