user: Question: When Joan Tewkesbury is the director what is the number in seasons?
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: [27.0, 1.0, '"Doogenstein"', 'Eric Laneuville', 'Linda Morris & Vic Rauseo', 'September 12, 1990', 1202.0]
SQL:

assistant: SELECT "No. in season" FROM "Table" WHERE "Directed by" = 'Joan Tewkesbury';