SQL: Dynamic Variable Names

Question

I am attempting to set variables whose names are dynamic in a stored procedure:

DECLARE @var01 varchar(50)  
DECLARE @var02 varchar(50) 
...
DECLARE @var30 varchar(50)
DECLARE @sql = varchar(max) 

DECLARE @loopcnter INT      

-- (Inside some loop where the loopcounter increments each iteration)
...
SET @sql = 'SET @var0'+CAST(@loopcntr AS Varchar)+'= '''+'somevalue'+''''
-- e.g.) SET @var01= 'somevale'
EXEC (@sql)

This doesn't work because the variables are declared in a different scope to that of the dynamic sql.

What is the correct way to dynamically set variables in this manner?

Answer 1

Well, it is not pretty, but you can do:

if @loopcntr = 1
    set var01 = 'somevalue'
else if @loopcntr = 2
    set var02 = 'whatever'
else if . . .

This should be sufficiently unpleasant that you might think of alternatives. Oh, here's a good one. Define a table variable and just add rows in for each value:

declare @vars table (
    id int identity(1, 1),
    loopcntr int,
    value varchar(255)
);

. . .
-- inside the loop
    insert into @vars(loopcntr, value)
        select @loopcntr, 'whatever';

When you want to get a variable, you can do:

declare @var varchar(255);
select @var = value from @vars where loopcntr = <the one I want>;