Which championship has Roger Federer as an opponent on a clay surface in a year earlier than 2007?
CREATE TABLE table_name_36 (
    championship VARCHAR,
    year VARCHAR,
    opponent VARCHAR,
    surface VARCHAR
)
SELECT championship FROM table_name_36 WHERE opponent = "roger federer" AND surface = "clay" AND year < 2007
Below are sql tables schemas paired with instruction that describes a task. Using valid SQLite, write a response that appropriately completes the request for the provided tables. ### Instruction: Which championship has Roger Federer as an opponent on a clay surface in a year earlier than 2007? ### Input: CREATE TABLE table_name_36 (
    championship VARCHAR,
    year VARCHAR,
    opponent VARCHAR,
    surface VARCHAR
) ### Response: SELECT championship FROM table_name_36 WHERE opponent = "roger federer" AND surface = "clay" AND year < 2007