user: Question: what is the total number of films directy and written by John Callaghan?
Columns: ['#', 'No.', 'Title', 'Directed by', 'Written by', 'Viewers', 'Original airdate', 'Prod. code']
Types: ['real', 'real', 'text', 'text', 'text', 'real', 'text', 'real']
Sample row: [26.0, 1.0, '"Streets of St. John\'s"', 'Keith Samples', 'Allan Hawco & Perry Chafe', 1361000.0, 'January11,2012', 301.0]
SQL:

assistant: SELECT COUNT("Directed by") FROM "Table" WHERE "Written by" = 'John Callaghan';