An Azure relational database service.
Let's say you have created a login on the master database named TestUser as shown below"
---- ON Master Level
CREATE USER TestUser
FOR LOGIN TestUser
WITH DEFAULT_SCHEMA = dbo
To create that login as a user on the QA database, connect to the QA database and run the following query:
---- ON SQL DB LEVEL
CREATE USER TestUser
FOR LOGIN TestUser
WITH DEFAULT_SCHEMA = dbo
GO
After that grant the user appropriate permissions to objects.
GRANT SELECT ON OBJECT::dbo.Sales TO TestUser;
GO
You can see the mapping between SIDs if you do as explained here.