Is there a way to make a TSQL variable constant?

Question

Is there a way to make a TSQL variable constant?

Answer 1

For enums or simple constants, a view with a single row has great performance and compile time checking / dependency tracking ( cause its a column name )

See Jared Ko's blog post https://blogs.msdn.microsoft.com/sql_server_appendix_z/2013/09/16/sql-server-variables-parameters-or-literals-or-constants/

create the view

 CREATE VIEW ShipMethods AS
 SELECT CAST(1 AS INT) AS [XRQ - TRUCK GROUND]
   ,CAST(2 AS INT) AS [ZY - EXPRESS]
   ,CAST(3 AS INT) AS [OVERSEAS - DELUXE]
  , CAST(4 AS INT) AS [OVERNIGHT J-FAST]
   ,CAST(5 AS INT) AS [CARGO TRANSPORT 5]

use the view

SELECT h.*
FROM Sales.SalesOrderHeader 
WHERE ShipMethodID = ( select [OVERNIGHT J-FAST] from ShipMethods  )