If your SQL Database uses SQL Authentication, you need to create a login for your colleague.
CREATE LOGIN [username] WITH PASSWORD = 'strong_password';
After creating the login, you need to create a user in the specific database and map it to the login.
CREATE USER [username] FOR LOGIN [username];
Grant the necessary permissions to the user. For querying, you typically need to grant the SELECT permission.
GRANT SELECT ON SCHEMA::[schema_name] TO [username];
If you want to grant more permissions, you can use roles like db_datareader:
ALTER ROLE db_datareader ADD MEMBER [username];
If your SQL Database uses Azure Active Directory (AAD) authentication, you need to add your colleague as a user in the database.
CREATE USER [******@domain.com] FROM EXTERNAL PROVIDER;
Then, grant the necessary permissions:
GRANT SELECT ON SCHEMA::[schema_name] TO [******@domain.com];