You can use dynamic SQL

I mean first check the version

Then build your SQL statement using a string variable, for example nvarchar(max)

Then execute it by sp_executeSQL

You can use dynamic SQL

I mean first check the version

Then build your SQL statement using a string variable, for example nvarchar(max)

Then execute it by sp_executeSQL

I think following script can work for this task

-- check for sql server version
declare @sql nvarchar(max)
if (select cast(left(cast(serverproperty('productversion') as varchar), 4) as decimal(5, 3))) >= 10 

set @sql = N'CREATE unique nonclustered index ix1_table ON [table] (column1, column2)
        WHERE column1 is not null and column2 is not null'

        ELSE

set @sql = N'CREATE nonclustered index ix1_table ON [table] (column1, column2)'


exec sp_executeSQL @sql