user: Question: Who directed the episode that aired on July15,2012?
Columns: ['Series #', 'Season #', 'Title', 'Directed by', 'Written by', 'Original air date', 'U.S. viewers (in millions)']
Types: ['real', 'real', 'text', 'text', 'text', 'text', 'text']
Sample row: [63.0, 1.0, '"The (Very) Big Bird Job"', 'John Rogers', 'John Rogers', 'July15,2012', '3.39']
SQL:

assistant: SELECT "Directed by" FROM "Table" WHERE "Original air date" = 'July15,2012';