Below is the list of tables from the database along with their columns and datatype. Need to generate an accurate SQL query for the question.
Only use the columns present in the respective table. Only use the columns which are required to generate the SQL query. Only use table joins if required and not otherwise.

### Tables ###
TABLE: CREATE TABLE table_1569516_1 ( platform VARCHAR, operator VARCHAR, service_pattern VARCHAR )

### Question ###
How many platforms have a southern opertator and the pattern is all stations via clapham junction?

### Accurate SQL ###

SELECT COUNT(platform) FROM table_1569516_1 WHERE operator = "Southern" AND service_pattern = "All stations via Clapham Junction"