Using portal.azure.com I've created SQL Server and SQL Database. I've set myself as the SQL Server admin.
I'm able to connect with my AAD account using SSMS.
I add another AAD users to my database:
use [MyDatabase]
CREATE USER [usename_emaildomain#EXT#@mydirectory.onmicrosoft.com] FROM EXTERNAL PROVIDER;
--add read permissions
EXEC sp_addrolemember 'db_datareader', [usename_emaildomain#EXT#@mydirectory.onmicrosoft.com]
But how do grant him admin rights so that he has full access to all databases? I'm able to sent only one admin in Azure Portal.