What was the surface for the opponent Roger Federer?
CREATE TABLE table_name_94 (surface VARCHAR, opponent VARCHAR)
SELECT surface FROM table_name_94 WHERE opponent = "roger federer"
<s>[INST] Write mssql query to answer the following question given the database schema. Schema: CREATE TABLE table_name_94 (surface VARCHAR, opponent VARCHAR) Question: What was the surface for the opponent Roger Federer? [/INST] SELECT surface FROM table_name_94 WHERE opponent = "roger federer" </s>