SELECT count(*) FROM Ref_locations
How many locations are listed in the database?
[Schema (values) (types)]: | cre_Doc_Tracking_DB |  Ref_Document_Types : document_type_code (text) , document_type_name (text) , document_type_description (text) | Ref_Calendar : calendar_date (text) , day_number (text) | Ref_Locations : location_code (text) , location_name (text) , location_description (text) | Roles : role_code (text) , role_name (text) , role_description (text) | All_Documents : document_id (text) , date_stored (text) , document_type_code (text) , document_name (text) , document_description (time) , other_details (number) | Employees : employee_id (text) , role_code (text) , employee_name (text) , gender_mfu (text) , date_of_birth (time) , other_details (number) | Document_Locations : document_id (text) , location_code (text) , date_in_location_from (text) , date_in_locaton_to (text) | Documents_to_be_Destroyed : document_id (text) , destruction_authorised_by_employee_id (text) , destroyed_by_employee_id (text) , planned_destruction_date (text) , actual_destruction_date (time) , other_details (number);