mssql: a result set was generated for update

When executing this snippet:
```
#+begin_src sql
declare @test varchar(100)
set @test = 'abc'
select @test 
#+end_src
```
I get this error:
```
#+RESULTS:
: Error: A result set was generated for update.
``` 

I'm using SQL Server. How should I execute this kind of scripts?  
