Announcing the public preview of Virtual Network service endpoints in Azure SQL Database. Azure SQL Database will allow you to set firewall rules for specific public IPs, and will give you the option of allowing all Azure Services’ IPs to connect to your Servers. If you're looking for finer grained connectivity limitations, you would have to provision a Static Public IP, which can be hard to manage and costly when done at scale. Virtual Network service endpoints will allow you to limit connectivity to your Azure SQL Database Servers from given subnets within a Virtual Network.
Learn more about Virtual Network service endpoints in Azure SQL Database.