What was the constructor in the Belgian Grand Prix round?
CREATE TABLE table_2911781_3 (constructor VARCHAR, grand_prix VARCHAR)
SELECT constructor FROM table_2911781_3 WHERE grand_prix = "Belgian grand_prix"
<s>[INST] Write mssql query to answer the following question given the database schema. Schema: CREATE TABLE table_2911781_3 (constructor VARCHAR, grand_prix VARCHAR) Question: What was the constructor in the Belgian Grand Prix round? [/INST] SELECT constructor FROM table_2911781_3 WHERE grand_prix = "Belgian grand_prix" </s>