T-SQL equivalent of C++ #define - sql-server

Question

I have an SQL-Script for changing the source tables of multiple views at once. To do so I would like to have something like
#define source theSourceTable
instead of finding and replacing the parts I need. My understanding is that this isn't possible with local variables but is there another way?

Answer 1

Like I mentioned in the comments, a SYNONYM, seems to the right idea here. As we have very little to work with, here is an overly simplified example:
USE Sandbox;
GO
--Create some sample tables
CREATE TABLE dbo.MyTable1 (MyColumn int);
INSERT INTO dbo.MyTable1 (MyColumn)
VALUES (1),(2);
CREATE TABLE dbo.MyTable2 (MyColumn int);
INSERT INTO dbo.MyTable2 (MyColumn)
VALUES (3),(4);
GO
--Create synonyms
CREATE SYNONYM dbo.MyTableA FOR dbo.MyTable1;
CREATE SYNONYM dbo.MyTableB FOR dbo.MyTable1;
GO
--Create views
CREATE VIEW MyView1 AS
SELECT MyColumn, 'View1' AS ObjectName
FROM dbo.MyTableA;
GO
CREATE VIEW MyView2 AS
SELECT MyColumn, 'View2' AS ObjectName
FROM dbo.MyTableB;
GO
CREATE VIEW MyView3 AS
SELECT A.MyColumn AS AColumn,
B.MyColumn AS BColumn,
'View3' AS ObjectName
FROM dbo.MyTableA A
CROSS JOIN dbo.MyTableB B;
GO
--Check data
SELECT *
FROM dbo.MyView1;
SELECT *
FROM dbo.MyView2;
SELECT *
FROM dbo.MyView3;
GO
--Create a new table
CREATE TABLE dbo.MyTable3 (MyColumn int);
INSERT INTO dbo.MyTable3 (MyColumn)
VALUES (5),(6);
GO
--Alter the synonyms
DROP SYNONYM dbo.MyTableA;
CREATE SYNONYM dbo.MyTableA FOR dbo.MyTable2;
DROP SYNONYM dbo.MyTableB;
CREATE SYNONYM dbo.MyTableB FOR dbo.MyTable3;
GO
--Check views again:
--Check data
SELECT *
FROM dbo.MyView1;
SELECT *
FROM dbo.MyView2;
SELECT *
FROM dbo.MyView3;
GO
--Clean up
DROP VIEW dbo.MyView1;
DROP VIEW dbo.MyView2;
DROP VIEW dbo.MyView3;
DROP SYNONYM dbo.MyTableA;
DROP SYNONYM dbo.MyTableB;
DROP TABLE dbo.MyTable1;
DROP TABLE dbo.MyTable2;
DROP TABLE dbo.MyTable3;
You will need to edit the existing DDL of all your views once, to use the new synonym's name instead, but after that you can simply recreate the synonyms and they will all be updated.

Answer 2

You might be able to use SQLCMD mode (activate with ALT-Q-M or toggle it in the Query menu in SSMS).
:SETVAR MyTable SomeTableName
CREATE OR ALTER VIEW dbo.myView
AS
SELECT * FROM dbo.$(MyTable)
GO
This will end up with a view that selects * from SomeTableName
Alternatively you can possibly use dynamic sql
DECLARE #sql VARCHAR(MAX)
DECLARE #myTable VARCHAR(100) = 'SomeTableName'
SET #sql = 'CREATE OR ALTER VIEW dbo.myView
AS
SELECT * FROM dbo.' + #myTable
EXEC(#sql)
which has the same end result.
(CREATE OR ALTER is SQL2016 syntactic sugar, if you are on an older version adjust accordingly)