Fully qualified name with dollar sign in SSDT project - tsql

Question

I was working on a tsql project, and I have noticed that the existing code used a syntax that I have not seen before. They have put a dollar sign in front of the database name for fully qualified address.
Here is one example :
SELECT c.AccountCode, FROM **[$(SmartAdmin)]**.dbo.Customers c
If I rename the database name as SmartAdmin.dbo.Customers, Visual Studio throws error says "contains an unresolved reference to an object".
It appears to be a Visual Studio related thing, can anyone explain what is this and
whether I can remove it.
Please see the attached screenshots, the last one comes from project solution file.

Answer 1

The [$(SmartAdmin)] syntax is used in an SSDT project to reference objects in other databases. To be precise, it is SQLCMD syntax.
If you have a database reference to SmartAdmin, and if the reference is set up so that [$(SmartAdmin)] properly references it, then that is not the problem. It looks like the problem is the other two references to [SmartAdmin]. Change them to look like [$(SmartAdmin)].dbo.whatever.
Example of why these references are useful: I just edited a stored procedure I had in SSDT to misspell a column name. Within seconds, the column name was underlined in red. I then deleted the database reference the column name depended on. The red underline went away. I added the database reference back, and the column was once again underlined in red. I corrected the column name, and the red underline went away.
Without the database reference, I would have had to wait until the stored procedure was deployed, or possibly executed, to see the error. With the database reference, I found out about the problem in the editor. Just like code.

Answer 2

It appears to me that your database is actually called $(SmartAdmin)
As the error suggests "contains an unresolved reference to an object". which means when you change the database name to SmartAdmin, it cannot find a database with this name on server.
If you want to change the database name you will need to execute the following statement and then you will be able to use that name in your statements.
USE master;
GO
EXEC sp_renamedb '$(SmartAdmin)', 'SmartAdmin';
GO
USE SmartAdmin; --<-- Now you will be able to connect to this database
GO -- without the dollar ($) sign.

Answer 3

This issue relates to Database Project External Database References. When you add another solution to a database project, you can specify the "Database Variable Name", in my case, it is $(SmartAdmin).
Please see this link for more information.
Thanks everybody for answering my question.