When did the ship that was commissioned July 1948 with a bow number of ps-31 launch?
CREATE TABLE table_name_22 (launched VARCHAR, commissioned VARCHAR, bow_number VARCHAR)
SELECT launched FROM table_name_22 WHERE commissioned = "july 1948" AND bow_number = "ps-31"
### Context: CREATE TABLE table_name_22 (launched VARCHAR, commissioned VARCHAR, bow_number VARCHAR) ### Question: When did the ship that was commissioned July 1948 with a bow number of ps-31 launch? ### Answer: SELECT launched FROM table_name_22 WHERE commissioned = "july 1948" AND bow_number = "ps-31"