Which technique can be used to create database firewall rules in Azure SQL Database?

Creating database firewall rules in Azure SQL Database can be accomplished through various methods, each tailored to different user preferences and requirements. The option highlighting the execution of a T-SQL command is indeed one of the valid techniques for establishing firewall rules.

This method allows users to manipulate database settings directly using SQL commands. Essentially, by executing specific T-SQL statements, you can configure which IP addresses are allowed to connect to your Azure SQL Database. This is particularly useful for database administrators who prefer working within SQL management environments or who need to script their configurations for consistency or automation.

The other techniques, such as utilizing Azure Portal settings, engaging Azure CLI commands, and implementing PowerShell scripts, all offer valid ways to manage Azure resources but do not focus directly on T-SQL commands for creating firewall rules. Each of these methods has its own advantages in terms of environment and use case, but for this specific question, the execution of T-SQL commands is highlighted correctly as a direct approach to managing firewall configurations at the database level.