Access Master DB Tables from User Database in SQL AZURE - sql

Question

I am trying to access sys.SQL_Logins on Master DB from a User Database so that I could join sys.sql_logins with sys.sysusers.
UserDatabase
SELECT DP.NAME, DP.sid, SU.sid
FROM sys.sql_logins DP
INNER JOIN SYS.sysusers SU
ON DP.name=SU.name
In Azure I am not able to do this, since I am not able to call master DB from UserDatbase. My objective was to compare SID of sys.sql_logins with sys.sqlusers from User Database.
Is there any way I could join these two tables in Azure.

Answer 1

You can only execute queries against a single database. However, you can set up an external table to point to the master database views. This code should get you there:
CREATE MASTER KEY; -- if your DB doesn't already have one
GO
CREATE DATABASE SCOPED CREDENTIAL AccessToMaster
WITH IDENTITY = 'yourmasterlogin', SECRET = 'yourpassword'; --TODO set a login name and password that can access the master database
GO
CREATE EXTERNAL DATA SOURCE MasterDatabase
WITH
(
TYPE = RDBMS,
LOCATION = N'yourserver.database.windows.net', --TODO replace your server name
DATABASE_NAME = N'master',
CREDENTIAL = AccessToMaster
);
GO
CREATE SCHEMA MasterDB AUTHORIZATION dbo;
GO
CREATE EXTERNAL TABLE MasterDB.sql_logins
(
[name] sysname,
principal_id int,
[sid] varbinary(85),
[is_disabled] bit
)
WITH
(
DATA_SOURCE = MasterDatabase,
SCHEMA_NAME = 'sys',
OBJECT_NAME = 'sql_logins'
);
GO
SELECT * FROM MasterDB.sql_logins;
GO