Access Control
Azure SQL Database limits access to databases through firewall rules, which are authentication techniques that require users to log in to a database with a valid username and password. Azure SQL Database further controls access to the underlying data through role-based permissions and row-level security. We'll now look at different access control methods in detail.
Firewall Rules
Azure SQL Database uses firewall rules to limit access to authorized IPs and block access to unauthorized IPs. This is the first level of access control provided by Azure SQL Database. Firewall rules can be created at the server level and the database level.
When an SQL database is provisioned, it's inaccessible to everyone. To make it accessible, you first need to add a server-level firewall rule. A firewall allows an IP or a range of IP addresses to connect to an Azure SQL database. You can then create database firewall rules to enable certain clients to access individual secure databases...