How many platforms have a southern opertator and the pattern is all stations via clapham junction?
CREATE TABLE table_1569516_1 (
    platform VARCHAR,
    operator VARCHAR,
    service_pattern VARCHAR
)
SELECT COUNT(platform) FROM table_1569516_1 WHERE operator = "Southern" AND service_pattern = "All stations via Clapham Junction"
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: How many platforms have a southern opertator and the pattern is all stations via clapham junction? ### Input: CREATE TABLE table_1569516_1 (
    platform VARCHAR,
    operator VARCHAR,
    service_pattern VARCHAR
) ### Response: SELECT COUNT(platform) FROM table_1569516_1 WHERE operator = "Southern" AND service_pattern = "All stations via Clapham Junction"