user: Question: what is the prod.code of the episode with original air date 01/12/1968?
Columns: ['#', 'Title', 'Director', 'Writer(s)', 'Originalairdate', 'Repeatairdate(s)', 'Prod.Code']
Types: ['real', 'text', 'text', 'text', 'text', 'text', 'text']
Sample row: [1.0, '"The Magic Shillelah"', 'Hollingsworth Morse', 'Frank Crow Leo Rifkin', '15/09/1968', '16/03/1969, 03/08/1969', '30-14']
SQL:

assistant: SELECT "Prod.Code" FROM "Table" WHERE "Originalairdate" = '01/12/1968';