Synapse snack: No new Azure SQL Database allowed

Case
I'm creating a new Synapse Analytics Workspace but it throws an error when deploying it: Location '' is not accepting creation of new Windows Azure SQL Database servers at this time.

Location '' is not accepting creation of new
Windows Azure SQL Database servers at this time.
(Code: SqlServerRegionDoesNotAllowProvisioning)

Solution
This doesn't mean that all Azure SQL Server are sold-out in your Azure region and that you have to wait until Microsoft buys more servers. It means SQL Server is not registered as an allowed resource provider on your Azure Subscription.

This will probably not happen very often because people who want to use Synapse have almost certainly used an Azure SQL Server before, but on a new subscription it is not registered by default.

When creating a new Synapse Workspace it does ask to first register the Microsoft.Synapse resource provider, but it doesn't mention that it also requires Microsoft.Sql.

The Synapse resource provider needs to be registered
to this subscription

Register Resource Providers

The solution is very simple, but it does require owner permissions on the Azure Subscription.

• In the Azure Portal go to Subscriptions (search for Subscriptions if it's not on the dashboard or in the menu)
• Click on your Subscription if you have multiple subscriptions to go to the overview page of your subscription
• In the left menu (at the bottom) click on Resource Providers
• Search for SQL
• Select Microsoft.SQL and click on the register button

Register a Resource Provider

Registering will take a couple of minutes and after that you can add a Synapse Workspace without the above error. One last observation... it doesn't create any (visible) Azure SQL Servers in any of the resource groups.

Deployment of Synapse Workspace succeeded