user: Question: How many episodes did Julie Martin wrote for the show If every episode has its own production code?
Columns: ['No. in series', 'No. in season', 'Title', 'Directed by', 'Written by', 'Original air date', 'Production code']
Types: ['real', 'real', 'text', 'text', 'text', 'text', 'real']
Sample row: [56.0, 1.0, '"Hostage (Part 1)"', 'Ted Demme', 'James Yoshimura', 'September20,1996', 501.0]
SQL:

assistant: SELECT COUNT("Production code") FROM "Table" WHERE "Written by" = 'Julie Martin';