Azure SQL - Cannot create encrypted master key - azure-sql-database

Question

I am trying to create a master key for my database, needed because I follow a tutorial to make cross db queries.
Tutorial: https://www.scarydba.com/2016/03/21/cross-database-queries-in-azure-sql-database/
It is a similar question to Cannot create master key for master database in azure sql, but I get the message:
Msg 15578, Level 16, State 1, Line 1 There is already a master key in
the database. Please drop it before performing this statement.
...when I am trying to create a master key which is encrypted. What do I do wrong and is there another option to make cross db calls with Azure?
I execute the following:
CREATE MASTER KEY ENCRYPTION BY PASSWORD='SUPERSTRONGPASSWORD'
GO
Regards

Answer 1

According my experience, the master key has already created and exist when we create the Azure SQL database.
When we create master key :
-- Create a db master key if one does not already exist, using your own password.
CREATE MASTER KEY ENCRYPTION BY PASSWORD='<EnterStrongPasswordHere>';
Since the master key is already exist, we could not create a new one.
For most situations, Azure SQL database cross db queries don't need create the master key.
For example, I use the bellow query to do cross db query from Mydatabase to Mydatabase2:
--The "username" and "password" should be the username and password used to log in into the Customers database.
CREATE DATABASE SCOPED CREDENTIAL ElasticDBQueryCred
WITH IDENTITY = '<username>',
SECRET = '<password>';
--To create an external data source, execute the following command on the Orders database:
CREATE EXTERNAL DATA SOURCE MyElasticDBQueryDataSrc WITH
(TYPE = RDBMS,
LOCATION = '<server_name>.database.windows.net',
DATABASE_NAME = 'Customers',
CREDENTIAL = ElasticDBQueryCred,
) ;
--Create an external table on the Orders database, which matches the definition of the CustomerInformation table:
CREATE EXTERNAL TABLE [dbo].[test]
( [id] [int] ,
[age] [int]
)
WITH
( DATA_SOURCE = MyElasticDBQueryDataSrc)
--query the table
select * from test
Test table in Mydatabase2:
Cross db query in Mydatabase:
For details, please reference: Get started with cross-database queries.
Hope this helps.