For all of my posts on using Azure Storage I’ve been using my online account etc. but ofcourse it’s more likely we’d normally want to test our code using an offline solution, hence it’s time to use the storage emulator.

In your App.config you need to have the following

<appSettings>
   <add key="StorageConnectionString" value="UseDevelopmentStorage=true;" />
</appSettings>

Now the following code (taken from my Azure table storage post) will use the local storage/Azure storage emulator.

var storageAccount = CloudStorageAccount.Parse(
   CloudConfigurationManager.GetSetting(
   "StorageConnectionString"));

var client = storageAccount.CreateCloudTableClient();
var table = client.GetTableReference("plants");

table.CreateIfNotExists();

var p = new Plant("Fruit", "Apple")
{
   Comment = "Can be used to make cider",
   MonthsToPlant = "Jan-Mar"
};

table.Execute(TableOperation.InsertOrMerge(p));

Note: If not already installed, install Azure Storage Emulator from https://azure.microsoft.com/en-gb/downloads/

and Azure storage emulator will be installed in

C:\Program Files (x86)\Microsoft SDKs\Azure\Storage Emulator

Microsoft Azure Storage Explorer can be used to view the storage data on your local machine/via the emulator and when you open the Development account in the Local and Attached Storage Accounts this will run the emulator, however I had several problems when running my client code.

This firstly resulted in no data in the table storage and then a 400 bad request.

So I had to open my command prompt at C:\Program Files (x86)\Microsoft SDKs\Azure\Storage Emulator (or run from the Window run/search textbox “Microsoft Azure Storage Emulator” to get a command prompt which will already have the emulator running and offers a CLI to interact with the emulator) and from here you can check the status, start, stop and create local storage using AzureStorageEmulator.exe. All looked fine but still didn’t work. Azure storage emulator, ultimately uses a default local MSSQL DB, so time to check things on the DB side.

Using Microsoft SQL Server Management Studio I connected to (local)\MSSQLLocalDb and under databases deleted the AzureStorangeEmulatorDb52 (ofcourse Azure Storage Emulator needs to have been stopped) as I was using Azure Storage Emulator 5.2, the DB name may differ depending on the version of the emulator you’re running.

From the Azure Storage Emulator, I ran

AzureStorageEmulator init

to recreate the DB (you might need to use the /forceCreate switch to reinitialize the DB). Oddly I still got an error from this command (see below)

Cannot create database 'AzureStorageEmulatorDb52' : The login already has an account under a different user name.
Changed database context to 'AzureStorageEmulatorDb52'..
One or more initialization actions have failed. Resolve these errors before attempting to run the storage emulator again.
Error: Cannot create database 'AzureStorageEmulatorDb52' : The login already has an account under a different user name.
Changed database context to 'AzureStorageEmulatorDb52'..

However if Microsoft SQL Server Management Studio all looked to be in place. So I re-ran my code and this time it worked.

Now we can run against the emulator and work away for the internet and/or reduce traffic and therefore possible costs of accessing Azure in the cloud.

References

Use the Azure storage emulator for development and testing