What are the unique block codes that have available rooms?
CREATE TABLE room (
    blockcode VARCHAR,
    unavailable VARCHAR
)
SELECT DISTINCT blockcode FROM room WHERE unavailable = 0
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: What are the unique block codes that have available rooms? ### Input: CREATE TABLE room (
    blockcode VARCHAR,
    unavailable VARCHAR
) ### Response: SELECT DISTINCT blockcode FROM room WHERE unavailable = 0